mm/folio_queue: delete __folio_order and use folio_order directly

__folio_order is the same as folio_order, remove __folio_order and then
just include mm.h and use folio_order directly.

Link: https://lkml.kernel.org/r/20250212025843.80283-2-liuye@kylinos.cn


Signed-off-by: Liu Ye <liuye@kylinos.cn>
Reviewed-by: Shivank Garg <shivankg@amd.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>