!5374 hwrng: core - Fix page fault dead lock on mmap-ed hwrng

Merge Pull Request from: @ci-robot 
 
PR sync from: Yi Yang <yiyang13@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/Y5UGZ7E2D6HEYP7R7FWIMHSCA6Y3D6KZ/ 
 
https://gitee.com/src-openeuler/kernel/issues/I99JR3 
 
Link:https://gitee.com/openeuler/kernel/pulls/5374

 

Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>