netfilter: conntrack: move sysctl pointer to net_generic infra

No need to keep this in struct net, place it in the net_generic data.
The sysctl pointer is removed from struct net in a followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack.h

@@ -47,6 +47,9 @@ struct nf_conntrack_net {
 	unsigned int users4;
 	unsigned int users6;
 	unsigned int users_bridge;
+#ifdef CONFIG_SYSCTL
+	struct ctl_table_header	*sysctl_header;
+#endif
 };
 
 #include <linux/types.h>

net/netfilter/nf_conntrack_standalone.c

@@ -1027,6 +1027,7 @@ static void nf_conntrack_standalone_init_gre_sysctl(struct net *net,
 
 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 {
+	struct nf_conntrack_net *cnet = net_generic(net, nf_conntrack_net_id);
 	struct nf_udp_net *un = nf_udp_pernet(net);
 	struct ctl_table *table;
 
@@ -1072,8 +1073,8 @@ static int nf_conntrack_standalone_init_sysctl(struct net *net)
 		table[NF_SYSCTL_CT_BUCKETS].mode = 0444;
 	}
 
-	net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
-	if (!net->ct.sysctl_header)
+	cnet->sysctl_header = register_net_sysctl(net, "net/netfilter", table);
+	if (!cnet->sysctl_header)
 		goto out_unregister_netfilter;
 
 	return 0;
@@ -1085,10 +1086,11 @@ static int nf_conntrack_standalone_init_sysctl(struct net *net)
 
 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 {
+	struct nf_conntrack_net *cnet = net_generic(net, nf_conntrack_net_id);
 	struct ctl_table *table;
 
-	table = net->ct.sysctl_header->ctl_table_arg;
-	unregister_net_sysctl_table(net->ct.sysctl_header);
+	table = cnet->sysctl_header->ctl_table_arg;
+	unregister_net_sysctl_table(cnet->sysctl_header);
 	kfree(table);
 }
 #else