* Reduce macsuck bandwidth usage to database
get_port_macs transfers a full list of all device_port.(mac,ip) in every macsuck.
With 8k devices and 40k interfaces it takes up around 15MB. Transferring them 8k times
during an 1h macsuck cycle requires bandwidth in the 300 to 400 mbit/s range.
This patch changes get_port_macs to be called inside walk_fwtable and only transfer
the macs found in the current target device/vlan.
