btrfs: don't opencode extent_changeset_free

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/qgroup.c

@@ -3625,8 +3625,7 @@ static int qgroup_reserve_data(struct btrfs_inode *inode,
 	qgroup_unreserve_range(inode, reserved, start, len);
 out:
 	if (new_reserved) {
-		extent_changeset_release(reserved);
-		kfree(reserved);
+		extent_changeset_free(reserved);
 		*reserved_ret = NULL;
 	}
 	return ret;