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>