Kernel: Remove sys$shbuf_seal() and userland wrappers

There are no remaining users of this syscall so let it go. :^)

Kernel/API/Syscall.h

@@ -129,7 +129,6 @@ namespace Kernel {
     S(chown)                  \
     S(fchmod)                 \
     S(symlink)                \
-    S(shbuf_seal)             \
     S(sendmsg)                \
     S(recvmsg)                \
     S(getsockopt)             \

Kernel/Process.h

@@ -338,7 +338,6 @@ public:
     int sys$shbuf_allow_pid(int, pid_t peer_pid);
     void* sys$shbuf_get(int shbuf_id, Userspace<size_t*> size);
     int sys$shbuf_release(int shbuf_id);
-    int sys$shbuf_seal(int shbuf_id);
     int sys$halt();
     int sys$reboot();
     int sys$realpath(Userspace<const Syscall::SC_realpath_params*>);

Kernel/SharedBuffer.cpp

@@ -185,17 +185,4 @@ void SharedBuffer::destroy_if_unused()
     }
 }
 
-void SharedBuffer::seal()
-{
-    LOCKER(shared_buffers().lock());
-    m_writable = false;
-    for (auto& ref : m_refs) {
-        // TODO: Region needs to be RefCounted!
-        if (auto* region = ref.region.unsafe_ptr()) {
-            region->set_writable(false);
-            region->remap();
-        }
-    }
-}
-
 }

Kernel/SharedBuffer.h

@@ -70,7 +70,6 @@ public:
     static void share_all_shared_buffers(Process& from_process, Process& with_process);
     size_t size() const { return m_vmobject->size(); }
     void destroy_if_unused();
-    void seal();
     AnonymousVMObject& vmobject() { return m_vmobject; }
     const AnonymousVMObject& vmobject() const { return m_vmobject; }
     int id() const { return m_shbuf_id; }

Kernel/Syscalls/shbuf.cpp

@@ -134,21 +134,4 @@ void* Process::sys$shbuf_get(int shbuf_id, Userspace<size_t*> user_size)
     return shared_buffer.ref_for_process_and_get_address(*this);
 }
 
-int Process::sys$shbuf_seal(int shbuf_id)
-{
-    REQUIRE_PROMISE(shared_buffer);
-    LOCKER(shared_buffers().lock());
-    auto it = shared_buffers().resource().find(shbuf_id);
-    if (it == shared_buffers().resource().end())
-        return -EINVAL;
-    auto& shared_buffer = *(*it).value;
-    if (!shared_buffer.is_shared_with(m_pid))
-        return -EPERM;
-#ifdef SHARED_BUFFER_DEBUG
-    klog() << "Sealing shared buffer " << shbuf_id;
-#endif
-    shared_buffer.seal();
-    return 0;
-}
-
 }