psi: using cpuacct_cgrp_id under CONFIG_CGROUP_CPUACCT

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4OF4N



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Fix the build error if CONFIG_CGROUP_CPUACCT is not enabled.

Fixes: a885e3f9 ("psi: support psi under cgroup v1")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Xunlei Pang <xlpang@linux.alibaba.com>
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>