cgroup: remove duplicate code in find_css_set()

The list head res->tasks gets initialized twice in find_css_set().
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/cgroup.c

@@ -470,7 +470,6 @@ static struct css_set *find_css_set(
 	/* Link this cgroup group into the list */
 	list_add(&res->list, &init_css_set.list);
 	css_set_count++;
-	INIT_LIST_HEAD(&res->tasks);
 	write_unlock(&css_set_lock);
 
 	return res;