inotify: Fix fsnotify_mark refcount leak in inotify_update_existing_watch()

Commit 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for
inotify_add_watch()") forgot to call fsnotify_put_mark() with
IN_MASK_CREATE after fsnotify_find_mark()

Fixes: 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()")
Signed-off-by: ZhangXiaoxu <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>

fs/notify/inotify/inotify_user.c

···
 	fsn_mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
 	if (!fsn_mark)
 		return -ENOENT;
-	else if (create)
-		return -EEXIST;
+	else if (create) {
+		ret = -EEXIST;
+		goto out;
+	}
 
 	i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
 
···
 	/* return the wd */
 	ret = i_mark->wd;
 
+out:
 	/* match the get from fsnotify_find_mark() */
 	fsnotify_put_mark(fsn_mark);