cgroup: mark cgroup_rmdir_waitq and cgroup_attach_proc() as static

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1042b3c..421557f 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -938,7 +938,7 @@
  *
  * CGRP_WAIT_ON_RMDIR flag is set under cgroup's inode->i_mutex;
  */
-DECLARE_WAIT_QUEUE_HEAD(cgroup_rmdir_waitq);
+static DECLARE_WAIT_QUEUE_HEAD(cgroup_rmdir_waitq);
 
 static void cgroup_wakeup_rmdir_waiter(struct cgroup *cgrp)
 {
@@ -2065,7 +2065,7 @@
  * Call holding cgroup_mutex and the group_rwsem of the leader. Will take
  * task_lock of each thread in leader's threadgroup individually in turn.
  */
-int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
+static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
 {
 	int retval, i, group_size;
 	struct cgroup_subsys *ss, *failed_ss = NULL;