sysctl: Remove the unnecessary sysctl_set parent concept.

In sysctl_net register the two networking roots in the proper order.

In register_sysctl walk the sysctl sets in the reverse order of the
sysctl roots.

Remove parent from ctl_table_set and setup_sysctl_set as it is no
longer needed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index ffd67a6..07c6b87 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -75,7 +75,6 @@
 static int __net_init sysctl_net_init(struct net *net)
 {
 	setup_sysctl_set(&net->sysctls,
-			 &net_sysctl_ro_root.default_set,
 			 is_seen);
 	return 0;
 }
@@ -96,9 +95,9 @@
 	ret = register_pernet_subsys(&sysctl_pernet_ops);
 	if (ret)
 		goto out;
-	register_sysctl_root(&net_sysctl_root);
-	setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);
+	setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL);
 	register_sysctl_root(&net_sysctl_ro_root);
+	register_sysctl_root(&net_sysctl_root);
 out:
 	return ret;
 }