cgroup: remove unused parameter in cgroup_task_migrate().

This patch removes unused parameter from cgroup_task_migrate().
Signed-off-by: NKevin Wilson <wkevils@gmail.com>
Acked-by: NAcked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

kernel/cgroup.c

@@ -1911,7 +1911,7 @@ EXPORT_SYMBOL_GPL(cgroup_taskset_size);
  *
  * Must be called with cgroup_mutex and threadgroup locked.
  */
-static void cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp,
+static void cgroup_task_migrate(struct cgroup *oldcgrp,
 				struct task_struct *tsk, struct css_set *newcg)
 {
 	struct css_set *oldcg;
@@ -2084,7 +2084,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
 	 */
 	for (i = 0; i < group_size; i++) {
 		tc = flex_array_get(group, i);
-		cgroup_task_migrate(cgrp, tc->cgrp, tc->task, tc->cg);
+		cgroup_task_migrate(tc->cgrp, tc->task, tc->cg);
 	}
 	/* nothing is sensitive to fork() after this point. */