media: ipu3-cio2: Use macros from mm.h

There are few nice macros in mm.h, some of which we may use here.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bingbu Cao <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/pci/intel/ipu3/ipu3-cio2.c

@@ -14,6 +14,7 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/pfn.h>
@@ -194,9 +195,8 @@ static void cio2_fbpt_entry_init_buf(struct cio2_device *cio2,
 	 * 4095 (PAGE_SIZE - 1) means every single byte in the last page
 	 * is available for DMA transfer.
 	 */
-	entry[1].second_entry.last_page_available_bytes =
-			(remaining & ~PAGE_MASK) ?
-				(remaining & ~PAGE_MASK) - 1 : PAGE_SIZE - 1;
+	remaining = offset_in_page(remaining) ?: PAGE_SIZE;
+	entry[1].second_entry.last_page_available_bytes = remaining - 1;
 	/* Fill FBPT */
 	remaining = length;
 	i = 0;