[LTP] [PATCH] syscalls/unlinkat01: Bugfix and update to new API

[zhaogongyi]

Hi Petr,

Thanks for your suggestions!

I have resubmit the patch as your review, please see: https://patchwork.ozlabs.org/project/ltp/patch/20210506093201.3129-1-zhaogongyi@huawei.com/

Thanks so much!

Best Regards,
Gongyi