USB: ohci-s3c2410: use resource_size()

This patch uses the resource_size help function instead of
manually calculating the resource size. It can reduce the chance
of introducing off-by-one errors.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ohci-s3c2410.c b/drivers/usb/host/ohci-s3c2410.c
index 16ec7da..5837d21 100644
--- a/drivers/usb/host/ohci-s3c2410.c
+++ b/drivers/usb/host/ohci-s3c2410.c
@@ -353,7 +353,7 @@
 		return -ENOMEM;
 
 	hcd->rsrc_start = dev->resource[0].start;
-	hcd->rsrc_len   = dev->resource[0].end - dev->resource[0].start + 1;
+	hcd->rsrc_len	= resource_size(&dev->resource[0]);
 
 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
 		dev_err(&dev->dev, "request_mem_region failed\n");