bonding: slight optimization for bond_alb_xmit()

The bond_alb_xmit will check the return value for
bond_dev_queue_xmit() every time, but the bond_dev_queue_xmit()
is always return 0, it is no need to check the value every time,
so remove the unneed judgement for the xmit path.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>