atheros: atl2: replace dev_kfree_skb_any() by dev_consume_skb_any()

atl2_xmit_frame() should call dev_consume_skb_any() when the
transmission is successful. It makes drop profiles more friendly.

Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>