hugetlb: use a folio in free_hpage_workfn()

	node = llist_del_all(&hpage_freelist);

	while (node) {

		struct page *page;

		struct folio *folio;

		struct hstate *h;

		page = container_of((struct address_space **)node,

				     struct page, mapping);

		folio = container_of((struct address_space **)node,

				     struct folio, mapping);

		node = node->next;

		page->mapping = NULL;

		folio->mapping = NULL;

		/*

		 * The VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio) in

		 * folio_hstate() is going to trigger because a previous call to

		 * remove_hugetlb_folio() will clear the hugetlb bit, so do

		 * not use folio_hstate() directly.

		 */

		h = size_to_hstate(page_size(page));

		h = size_to_hstate(folio_size(folio));

		__update_and_free_hugetlb_folio(h, page_folio(page));

		__update_and_free_hugetlb_folio(h, folio);

		cond_resched();

	}