ipvs: fix some sparse warnings

Add missing __percpu annotations and make ip_vs_net_id static.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

diff --cc include/net/ip_vs.h
Simple merge

diff --cc net/netfilter/ipvs/ip_vs_core.c
Simple merge

diff --cc net/netfilter/ipvs/ip_vs_est.c
Simple merge