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>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 4d2f215..010eea0 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1307,6 +1307,8 @@
 			if (err)
 				goto out_orphans;
 			err = ubifs_rcvry_gc_commit(c);
+			if (err)
+				goto out_orphans;
 		} else {
 			err = take_gc_lnum(c);
 			if (err)