cgroup: kill unused variable

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 5987dcc..3fe21e1 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2402,7 +2402,6 @@
 static int proc_cgroupstats_show(struct seq_file *m, void *v)
 {
 	int i;
-	struct cgroupfs_root *root;
 
 	seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\n");
 	mutex_lock(&cgroup_mutex);