netfilter: ipv6: add IPv6 NAT support

Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index df0a545..0318104 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -42,6 +42,7 @@
 #ifdef CONFIG_SECURITY
 	struct xt_table		*ip6table_security;
 #endif
+	struct xt_table		*ip6table_nat;
 #endif
 	struct rt6_info         *ip6_null_entry;
 	struct rt6_statistics   *rt6_stats;