UBIFS: check return code

The error code from 'ubifs_rcvry_gc_commit()' was ignored, so UBIFS
failed to recover and continued. Instead, we should refuse mounting
the file-system.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

fs/ubifs/super.c

@@ -1307,6 +1307,8 @@ static int mount_ubifs(struct ubifs_info *c)
 			if (err)
 				goto out_orphans;
 			err = ubifs_rcvry_gc_commit(c);
+			if (err)
+				goto out_orphans;
 		} else {
 			err = take_gc_lnum(c);
 			if (err)