file_systems: fs_read_link() doesn't use a user buffer

introduced in hrev26728 and hrev54107.

Change-Id: I3e98d54e829bcce559c43a8ee1abe4d889c0a571
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2819
Reviewed-by: waddlesplash <[email protected]>

src/add-ons/kernel/file_systems/bfs/kernel_interface.cpp

@@ -1606,7 +1606,8 @@ bfs_read_link(fs_volume* _volume, fs_vnode* _node, char* buffer,
 
 	*_bufferSize = linkLength;
 
-	return user_memcpy(buffer, inode->Node().short_symlink, bytesToCopy);
+	memcpy(buffer, inode->Node().short_symlink, bytesToCopy);
+	return B_OK;
 }