netfilter: conntrack: pass hook state to log functions

The packet logger backend is unable to provide the incoming (or
outgoing) interface name because that information isn't available.

Pass the hook state, it contains the network namespace, the protocol
family, the network interfaces and other things.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>