IPVS: Free resources on module removal

This resolves a panic on module removal.
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

net/netfilter/ipvs/ip_vs_ctl.c

@@ -3771,6 +3771,7 @@ int __init ip_vs_control_init(void)
 void ip_vs_control_cleanup(void)
 {
 	EnterFunction(2);
+	unregister_netdevice_notifier(&ip_vs_dst_notifier);
 	ip_vs_genl_unregister();
 	nf_unregister_sockopt(&ip_vs_sockopts);
 	LeaveFunction(2);