bonding: use compare_ether_addr_64bits() in ALB

We can speedup ether addresses compares using compare_ether_addr_64bits()
instead of memcmp(). We make sure all operands are at least 8 bytes long and
16bits aligned (or better, long word aligned if possible)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>