Kernel: Remove redundant [[nodiscard]] on KResult return values

Both KResult and KResultOr are [[nodiscard]] at the class level,
so there's no need to have functions return `[[nodiscard]] KResult`.

Kernel/API/KResult.h

@@ -141,7 +141,7 @@ public:
         return m_error;
     }
 
-    [[nodiscard]] KResult result() const { return m_is_error ? m_error : KSuccess; }
+    KResult result() const { return m_is_error ? m_error : KSuccess; }
 
     [[nodiscard]] ALWAYS_INLINE T& value() &
     {
@@ -167,7 +167,7 @@ public:
         return released_value;
     }
 
-    [[nodiscard]] KResult release_error()
+    KResult release_error()
     {
         VERIFY(m_is_error);
         return m_error;

Kernel/Coredump.h

@@ -18,7 +18,7 @@ public:
     static KResultOr<NonnullOwnPtr<Coredump>> try_create(NonnullRefPtr<Process>, StringView output_path);
 
     ~Coredump() = default;
-    [[nodiscard]] KResult write();
+    KResult write();
 
 private:
     Coredump(NonnullRefPtr<Process>, NonnullRefPtr<FileDescription>);

Kernel/Devices/AsyncDeviceRequest.h

@@ -90,7 +90,7 @@ public:
     }
 
     template<size_t BUFFER_BYTES, typename... Args>
-    [[nodiscard]] KResultOr<size_t> write_to_buffer_buffered(UserOrKernelBuffer& buffer, Args... args)
+    KResultOr<size_t> write_to_buffer_buffered(UserOrKernelBuffer& buffer, Args... args)
     {
         if (in_target_context(buffer))
             return buffer.write_buffered<BUFFER_BYTES>(forward<Args>(args)...);
@@ -108,7 +108,7 @@ public:
     }
 
     template<size_t BUFFER_BYTES, typename... Args>
-    [[nodiscard]] KResultOr<size_t> read_from_buffer_buffered(const UserOrKernelBuffer& buffer, Args... args)
+    KResultOr<size_t> read_from_buffer_buffered(const UserOrKernelBuffer& buffer, Args... args)
     {
         if (in_target_context(buffer))
             return buffer.read_buffered<BUFFER_BYTES>(forward<Args>(args)...);

Kernel/DoubleBuffer.h

@@ -17,19 +17,19 @@ namespace Kernel {
 class DoubleBuffer {
 public:
     [[nodiscard]] static OwnPtr<DoubleBuffer> try_create(size_t capacity = 65536);
-    [[nodiscard]] KResultOr<size_t> write(const UserOrKernelBuffer&, size_t);
+    KResultOr<size_t> write(const UserOrKernelBuffer&, size_t);
-    [[nodiscard]] KResultOr<size_t> write(const u8* data, size_t size)
+    KResultOr<size_t> write(const u8* data, size_t size)
     {
         return write(UserOrKernelBuffer::for_kernel_buffer(const_cast<u8*>(data)), size);
     }
-    [[nodiscard]] KResultOr<size_t> read(UserOrKernelBuffer&, size_t);
+    KResultOr<size_t> read(UserOrKernelBuffer&, size_t);
-    [[nodiscard]] KResultOr<size_t> read(u8* data, size_t size)
+    KResultOr<size_t> read(u8* data, size_t size)
     {
         auto buffer = UserOrKernelBuffer::for_kernel_buffer(data);
         return read(buffer, size);
     }
-    [[nodiscard]] KResultOr<size_t> peek(UserOrKernelBuffer&, size_t);
+    KResultOr<size_t> peek(UserOrKernelBuffer&, size_t);
-    [[nodiscard]] KResultOr<size_t> peek(u8* data, size_t size)
+    KResultOr<size_t> peek(u8* data, size_t size)
     {
         auto buffer = UserOrKernelBuffer::for_kernel_buffer(data);
         return peek(buffer, size);

Kernel/KString.h

@@ -23,7 +23,7 @@ public:
 
     void operator delete(void*);
 
-    [[nodiscard]] KResultOr<NonnullOwnPtr<KString>> try_clone() const;
+    KResultOr<NonnullOwnPtr<KString>> try_clone() const;
 
     [[nodiscard]] bool is_empty() const { return m_length == 0; }
     [[nodiscard]] size_t length() const { return m_length; }

Kernel/StdLib.cpp

@@ -193,7 +193,7 @@ KResult copy_from_user(void* dest_ptr, void const* src_ptr, size_t n)
     return KSuccess;
 }
 
-[[nodiscard]] KResult memset_user(void* dest_ptr, int c, size_t n)
+KResult memset_user(void* dest_ptr, int c, size_t n)
 {
     bool is_user = Kernel::Memory::is_user_range(VirtualAddress(dest_ptr), n);
     if (!is_user)

Kernel/StdLib.h

@@ -34,9 +34,9 @@ KResultOr<Time> copy_time_from_user(Userspace<T*>);
 [[nodiscard]] Optional<u32> user_atomic_fetch_or_relaxed(volatile u32* var, u32 val);
 [[nodiscard]] Optional<u32> user_atomic_fetch_xor_relaxed(volatile u32* var, u32 val);
 
-[[nodiscard]] KResult copy_to_user(void*, const void*, size_t);
+KResult copy_to_user(void*, const void*, size_t);
-[[nodiscard]] KResult copy_from_user(void*, const void*, size_t);
+KResult copy_from_user(void*, const void*, size_t);
-[[nodiscard]] KResult memset_user(void*, int, size_t);
+KResult memset_user(void*, int, size_t);
 
 extern "C" {
 

Kernel/UserOrKernelBuffer.h

@@ -54,7 +54,7 @@ public:
         return offset_buffer;
     }
 
-    [[nodiscard]] KResultOr<NonnullOwnPtr<KString>> try_copy_into_kstring(size_t) const;
+    KResultOr<NonnullOwnPtr<KString>> try_copy_into_kstring(size_t) const;
     [[nodiscard]] bool write(const void* src, size_t offset, size_t len);
     [[nodiscard]] bool write(const void* src, size_t len)
     {
@@ -82,7 +82,7 @@ public:
     }
 
     template<size_t BUFFER_BYTES, typename F>
-    [[nodiscard]] KResultOr<size_t> write_buffered(size_t offset, size_t len, F f)
+    KResultOr<size_t> write_buffered(size_t offset, size_t len, F f)
     {
         if (!m_buffer)
             return EFAULT;
@@ -113,13 +113,13 @@ public:
         return nwritten;
     }
     template<size_t BUFFER_BYTES, typename F>
-    [[nodiscard]] KResultOr<size_t> write_buffered(size_t len, F f)
+    KResultOr<size_t> write_buffered(size_t len, F f)
     {
         return write_buffered<BUFFER_BYTES, F>(0, len, f);
     }
 
     template<size_t BUFFER_BYTES, typename F>
-    [[nodiscard]] KResultOr<size_t> read_buffered(size_t offset, size_t len, F f) const
+    KResultOr<size_t> read_buffered(size_t offset, size_t len, F f) const
     {
         if (!m_buffer)
             return EFAULT;
@@ -149,7 +149,7 @@ public:
         return nread;
     }
     template<size_t BUFFER_BYTES, typename F>
-    [[nodiscard]] KResultOr<size_t> read_buffered(size_t len, F f) const
+    KResultOr<size_t> read_buffered(size_t len, F f) const
     {
         return read_buffered<BUFFER_BYTES, F>(0, len, f);
     }