netfilter: bridge: reduce nf_bridge_info to 32 bytes again

We can use union for most of the temporary cruft (original ipv4/ipv6
address, source mac, physoutdev) since they're used during different
stages of br netfilter traversal.

Also get rid of the last two ->mask users.

Shrinks struct from 48 to 32 on 64bit arch.

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

diff --cc include/linux/netfilter_bridge.h
Simple merge

diff --cc include/linux/skbuff.h
Simple merge

diff --cc net/bridge/br_netfilter_hooks.c
Simple merge

diff --cc net/bridge/br_netfilter_ipv6.c
Simple merge

diff --cc net/ipv4/netfilter/nf_defrag_ipv4.c
Simple merge

diff --cc net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
Simple merge