mm: use is_zone_movable_page() helper

Use is_zone_movable_page() helper to simplify code.

Link: https://lkml.kernel.org/r/20220726131135.146912-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory_hotplug.c

@@ -932,7 +932,7 @@ static struct zone *auto_movable_zone_for_pfn(int nid,
 			if (!page)
 				continue;
 			/* If anything is !MOVABLE online the rest !MOVABLE. */
-			if (page_zonenum(page) != ZONE_MOVABLE)
+			if (!is_zone_movable_page(page))
 				goto kernel_zone;
 			online_pages += PAGES_PER_SECTION;
 		}