mm/hugetlb: convert get_hwpoison_huge_page() to folios

Straightforward conversion of get_hwpoison_huge_page() to
get_hwpoison_hugetlb_folio().  Reduces two references to a head page in
memory-failure.c

[arnd@arndb.de: fix get_hwpoison_hugetlb_folio() stub]
  Link: https://lkml.kernel.org/r/20230119111920.635260-1-arnd@kernel.org
Link: https://lkml.kernel.org/r/20230118174039.14247-1-sidhartha.kumar@oracle.com


Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>