USB: gadget: imx_udc: Use resource size

Use the resource_size function instead of manually calculating the
resource size. This reduces the chance of introducing off-by-one errors.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/imx_udc.c b/drivers/usb/gadget/imx_udc.c
index c52a681..01ee0b9 100644
--- a/drivers/usb/gadget/imx_udc.c
+++ b/drivers/usb/gadget/imx_udc.c
@@ -1402,7 +1402,8 @@
 	struct clk *clk;
 	void __iomem *base;
 	int ret = 0;
-	int i, res_size;
+	int i;
+	resource_size_t res_size;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
@@ -1416,7 +1417,7 @@
 		return -ENODEV;
 	}
 
-	res_size = res->end - res->start + 1;
+	res_size = resource_size(res);
 	if (!request_mem_region(res->start, res_size, res->name)) {
 		dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
 			res_size, res->start);
@@ -1527,8 +1528,7 @@
 	clk_disable(imx_usb->clk);
 	iounmap(imx_usb->base);
 
-	release_mem_region(imx_usb->res->start,
-		imx_usb->res->end - imx_usb->res->start + 1);
+	release_mem_region(imx_usb->res->start, resource_size(imx_usb->res));
 
 	if (pdata->exit)
 		pdata->exit(&pdev->dev);