ipv6: delete protocol and unregister rtnetlink when cleanup

pim6_protocol was added when initiation, but it not deleted.
Similarly, unregister RTNL_FAMILY_IP6MR rtnetlink.
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Reviewed-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ip6mr.c

@@ -1439,6 +1439,10 @@ int __init ip6_mr_init(void)
 
 void ip6_mr_cleanup(void)
 {
+	rtnl_unregister(RTNL_FAMILY_IP6MR, RTM_GETROUTE);
+#ifdef CONFIG_IPV6_PIMSM_V2
+	inet6_del_protocol(&pim6_protocol, IPPROTO_PIM);
+#endif
 	unregister_netdevice_notifier(&ip6_mr_notifier);
 	unregister_pernet_subsys(&ip6mr_net_ops);
 	kmem_cache_destroy(mrt_cachep);