fsnotify: Remove useless list deletion and comment

After removing all the indirection it is clear that

hlist_del_init_rcu(&mark->obj_list);

in fsnotify_destroy_marks() is not needed as the mark gets removed from
the list shortly afterwards in fsnotify_destroy_mark() ->
fsnotify_detach_mark() -> fsnotify_detach_from_object(). Also there is
no problem with mark being visible on object list while we call
fsnotify_destroy_mark() as parallel destruction of marks from several
places is properly handled (as mentioned in the comment in
fsnotify_destroy_marks(). So just remove the list removal and also the
stale comment.

Reviewed-by: Miklos Szeredi <[email protected]>
Reviewed-by: Amir Goldstein <[email protected]>
Signed-off-by: Jan Kara <[email protected]>

fs/notify/mark.c

@@ -620,12 +620,6 @@ void fsnotify_destroy_marks(struct fsnotify_mark_connector *conn)
 		}
 		mark = hlist_entry(conn->list.first, struct fsnotify_mark,
 				   obj_list);
-		/*
-		 * We don't update i_fsnotify_mask / mnt_fsnotify_mask here
-		 * since inode / mount is going away anyway. So just remove
-		 * mark from the list.
-		 */
-		hlist_del_init_rcu(&mark->obj_list);
 		fsnotify_get_mark(mark);
 		spin_unlock(lock);
 		fsnotify_destroy_mark(mark, mark->group);