netfilter: nf_conntrack_h323: Remove deprecated config check

CONFIG_NF_CONNTRACK_IPV6 has been deprecated so replace it with a check
for IPV6 instead.

Use nf_ip6_route6() instead of v6ops->route() and keep the IS_MODULE()
in nf_ipv6_ops as mentioned by Florian so that direct calls are used
when IPV6 is builtin and indirect calls are used only when IPV6 is a
module.

Fixes: a0ae2562 ("netfilter: conntrack: remove l3proto abstraction")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_h323_main.c

@@ -748,24 +748,19 @@ static int callforward_do_filter(struct net *net,
 		}
 		break;
 	}
-#if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
+#if IS_ENABLED(CONFIG_IPV6)
 	case AF_INET6: {
-		const struct nf_ipv6_ops *v6ops;
 		struct rt6_info *rt1, *rt2;
 		struct flowi6 fl1, fl2;
 
-		v6ops = nf_get_ipv6_ops();
-		if (!v6ops)
-			return 0;
-
 		memset(&fl1, 0, sizeof(fl1));
 		fl1.daddr = src->in6;
 
 		memset(&fl2, 0, sizeof(fl2));
 		fl2.daddr = dst->in6;
-		if (!v6ops->route(net, (struct dst_entry **)&rt1,
+		if (!nf_ip6_route(net, (struct dst_entry **)&rt1,
 				  flowi6_to_flowi(&fl1), false)) {
-			if (!v6ops->route(net, (struct dst_entry **)&rt2,
+			if (!nf_ip6_route(net, (struct dst_entry **)&rt2,
 					  flowi6_to_flowi(&fl2), false)) {
 				if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
 						    rt6_nexthop(rt2, &fl2.daddr)) &&