mm, hwpoison: remove recalculating hpage

mainline inclusion
from linux-v5.10-rc1
commit 1b473bec
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4LE22


CVE: NA

--------------------------------

hpage is never used after try_to_split_thp_page() in memory_failure(), so
we don't have to update hpage.  So let's not recalculate/use hpage.

Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>