mm: prefer xxx_page() alloc/free functions for order-0 pages

Update instances of alloc_pages(..., 0), __get_free_pages(..., 0) and
__free_pages(..., 0) to use alloc_page(), __get_free_page() and
__free_page() respectively in core code.

Link: https://lkml.kernel.org/r/50c48ca4789f1da2a65795f2346f5ae3eff7d665.1678710232.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 7887cc2..4362021 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -1048,7 +1048,7 @@ static void __init destroy_args(struct pgtable_debug_args *args)
 
 	if (args->pte_pfn != ULONG_MAX) {
 		page = pfn_to_page(args->pte_pfn);
-		__free_pages(page, 0);
+		__free_page(page);
 
 		args->pte_pfn = ULONG_MAX;
 	}
@@ -1290,7 +1290,7 @@ static int __init init_args(struct pgtable_debug_args *args)
 		}
 	}
 
-	page = alloc_pages(GFP_KERNEL, 0);
+	page = alloc_page(GFP_KERNEL);
 	if (page)
 		args->pte_pfn = page_to_pfn(page);