btrfs: qgroup: return correct error when deleting qgroup relation item

btrfs: qgroup: return correct error when deleting qgroup relation item

If we fail to delete the second qgroup relation item, we end up returning
success or -ENOENT in case the first item does not exist, instead of
returning the error from the second item deletion.

Fixes: 73798c465b66 ("btrfs: qgroup: Try our best to delete qgroup relations")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>