ext4: fix missing cleanup if ext4_alloc_flex_bg_array() fails while resizing

Fixes: 117fff10d7f1 ("ext4: grow the s_flex_groups array as needed ...")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 3.7

fs/ext4/resize.c

@@ -2022,7 +2022,7 @@ retry:
 
 	err = ext4_alloc_flex_bg_array(sb, n_group + 1);
 	if (err)
-		return err;
+		goto out;
 
 	err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
 	if (err)