arp: Fix check for ARP entry existence when saving packets.
arp: Fix check for ARP entry existence when saving packets.

Apparently the check for MAC address under ARP_SANITY_CHECK in
ofp_arp_save_ipv4_pkt() was supposed to check the last byte of the
address, but there's an off by one error. Since the MAC address is
stored as an uint64_t, fix this by checking the whole field.

Signed-off-by: Jere Leppänen <14957520de8d9815e0c353a07fe23c737f0171e9@nokia.com>
Reviewed-by: Sorin Vultureanu <8013ba55f8675034bc2ab0d6c3a1c9650437ca36@enea.com>

OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp