mm/hugetlb: convert restore_reserve_on_error() to folios

Use the hugetlb folio flag macros inside restore_reserve_on_error() and
update the comments to reflect the use of folios.

Link: https://lkml.kernel.org/r/20230113223057.173292-8-sidhartha.kumar@oracle.com


Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>