ubifs: Fix ubifs_tnc_lookup() usage in do_kill_orphans()

Orphans are allowed to point to deleted inodes.
So -ENOENT is not a fatal error.
Reported-by: Кочетков Максим <fido_max@inbox.ru>
Reported-and-tested-by: "Christian Berger" <Christian.Berger@de.bosch.com>
Tested-by: Karl Olsen <karl@micro-technic.com>
Tested-by: Jef Driesen <jef.driesen@niko.eu>
Fixes: ee1438ce ("ubifs: Check link count of inodes when killing orphans.")
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/orphan.c

@@ -688,14 +688,14 @@ static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 
 			ino_key_init(c, &key1, inum);
 			err = ubifs_tnc_lookup(c, &key1, ino);
-			if (err)
+			if (err && err != -ENOENT)
 				goto out_free;
 
 			/*
 			 * Check whether an inode can really get deleted.
 			 * linkat() with O_TMPFILE allows rebirth of an inode.
 			 */
-			if (ino->nlink == 0) {
+			if (err == 0 && ino->nlink == 0) {
 				dbg_rcvry("deleting orphaned inode %lu",
 					  (unsigned long)inum);