mm/hugetlb: mm/memory_hotplug: use a folio in scan_movable_pages()

By using a folio in scan_movable_pages() we convert the last user of the
page-based hugetlb information macro functions to the folio version. 
After this conversion, we can safely remove the page-based definitions
from include/linux/hugetlb.h.

Link: https://lkml.kernel.org/r/20240530171427.242018-1-sidhartha.kumar@oracle.com


Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>