sched classifier: make cgroup table local

Doesn't need to be global.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_cgroup.c

@@ -103,7 +103,7 @@ static struct cftype ss_files[] = {
 	{ }	/* terminate */
 };
 
-struct cgroup_subsys net_cls_subsys = {
+static struct cgroup_subsys net_cls_subsys = {
 	.name		= "net_cls",
 	.css_alloc	= cgrp_css_alloc,
 	.css_online	= cgrp_css_online,