Use the possibly more efficient ether_addr_equal or
ether_addr_equal_unaligned to instead of memcmp.

Cc: Ariel Elior <ariele@broadcom.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>