!3209 exec: Remove redundant check in do_open_execat/uselib

Merge Pull Request from: @ci-robot 
 
PR sync from: Zhihao Cheng <chengzhihao1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/KJYVXM32CUBXAOXERRGVUDXPSXTVJYMB/ 
 
https://gitee.com/openeuler/kernel/issues/I8LX53 
 
Link:https://gitee.com/openeuler/kernel/pulls/3209

 

Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>