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

BugLink: https://bugs.launchpad.net/bugs/1810947

commit f348e224 upstream.

Fixes: 117fff10 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/ext4/resize.c

@@ -1990,7 +1990,7 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
 
 	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)