Kernel: Allow read access sparingly to some /sys/kernel directory nodes

Those nodes are not exposing any sensitive information so there's no
harm in exposing them.

Kernel/FileSystem/SysFS/Subsystems/Kernel/MemoryStatus.h

@@ -23,6 +23,8 @@ public:
 private:
     explicit SysFSMemoryStatus(SysFSDirectory const& parent_directory);
     virtual ErrorOr<void> try_generate(KBufferBuilder& builder) override;
+
+    virtual bool is_readable_by_jailed_processes() const override { return true; }
 };
 
 }