ipvs: Better derivation of ipvs in ip_vs_tunnel_xmit

Don't use "net_ipvs(skb_net(skb))" as skb_net is a bad hack.  Instead
use cp->ipvs and ipvs->net for the net.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

net/netfilter/ipvs/ip_vs_xmit.c

@@ -971,8 +971,8 @@ int
 ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
-	struct net *net = skb_net(skb);
-	struct netns_ipvs *ipvs = net_ipvs(net);
+	struct netns_ipvs *ipvs = cp->ipvs;
+	struct net *net = ipvs->net;
 	struct rtable *rt;			/* Route to the other host */
 	__be32 saddr;				/* Source for tunnel */
 	struct net_device *tdev;		/* Device to other host */