cgroup: Avoid unnecessary looping in cgroup_no_v1()

No need to continue the for_each_subsys loop after the token matches the
name of subsys and cgroup_no_v1_mask is set.
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/cgroup/cgroup-v1.c

@@ -1335,6 +1335,7 @@ static int __init cgroup_no_v1(char *str)
 				continue;
 
 			cgroup_no_v1_mask |= 1 << i;
+			break;
 		}
 	}
 	return 1;