net: netxen: slight optimization of addr compare

Use possibly more efficient ether_addr_equal
to instead of memcmp.

Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Sony Chacko <sony.chacko@qlogic.com>
Cc: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>