fuse: annotate lock in fuse_reverse_inval_entry()

Add missing inode lock annotatation; found by syzbot.

Reported-and-tested-by: syzbot+9f747458f5990eaa8d43@syzkaller.appspotmail.com
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

fs/fuse/dir.c

@@ -1079,7 +1079,7 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
 	if (!parent)
 		return -ENOENT;
 
-	inode_lock(parent);
+	inode_lock_nested(parent, I_MUTEX_PARENT);
 	if (!S_ISDIR(parent->i_mode))
 		goto unlock;