sctp: Add infrastructure for per net sysctls

Start with an empty sctp_net_table that will be populated as the various
tunable sysctls are made per net.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index d58db31..0f2342b 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -1169,6 +1169,10 @@
 {
 	int status;
 
+	status = sctp_sysctl_net_register(net);
+	if (status)
+		goto err_sysctl_register;
+
 	/* Allocate and initialise sctp mibs.  */
 	status = init_sctp_mibs(net);
 	if (status)
@@ -1208,6 +1212,8 @@
 err_init_proc:
 	cleanup_sctp_mibs(net);
 err_init_mibs:
+	sctp_sysctl_net_unregister(net);
+err_sysctl_register:
 	return status;
 }
 
@@ -1224,6 +1230,7 @@
 
 	sctp_proc_exit(net);
 	cleanup_sctp_mibs(net);
+	sctp_sysctl_net_unregister(net);
 }
 
 static struct pernet_operations sctp_net_ops = {