hostnet: improve logging of filtered packets
hostnet: improve logging of filtered packets

When we drop a packet with an unexpected source IP, also log the expected
source IPs for easy visual inspection.

In particular this is helpful in cases where the DHCP server gave out the
wrong IP address because the client presented with the wrong MAC address.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@docker.com>

djs55/vpnkit,djs55/vpnkit,samoht/vpnkit,djs55/vpnkit