[NETFILTER]: constify nf_afinfo

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 945e6ae..2e06724 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -124,7 +124,7 @@
 
 EXPORT_SYMBOL(nf_ip6_checksum);
 
-static struct nf_afinfo nf_ip6_afinfo = {
+static const struct nf_afinfo nf_ip6_afinfo = {
 	.family		= AF_INET6,
 	.checksum	= nf_ip6_checksum,
 	.route		= nf_ip6_route,