Kernel: Don't rewrite the whole file on sys$msync

Author: https://github.com/Hendiadyoin1
Commit: c7b90fa7d3
Pull-request: https://github.com/SerenityOS/serenity/pull/10957
Reviewed-by: https://github.com/Dexesttp

Kernel/Memory/SharedInodeVMObject.h

@@ -18,7 +18,7 @@ public:
     static ErrorOr<NonnullRefPtr<SharedInodeVMObject>> try_create_with_inode(Inode&);
     virtual ErrorOr<NonnullRefPtr<VMObject>> try_clone() override;
 
-    ErrorOr<void> sync();
+    ErrorOr<void> sync(off_t offset_in_pages = 0, size_t pages = -1);
 
 private:
     virtual bool is_shared_inode() const override { return true; }