[media] Drivers: staging: media: davinci_vpfe: Use resource_size function

Use resource_size function on resource object instead of explicit
computation.
Signed-off-by: NAlexandru Gheorghiu <gheorghiuandru@gmail.com>
Acked-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/media/davinci_vpfe/dm365_ipipeif.c

@@ -1065,7 +1065,6 @@ vpfe_ipipeif_cleanup(struct vpfe_ipipeif_device *ipipeif,
 	iounmap(ipipeif->ipipeif_base_addr);
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
 	if (res)
-		release_mem_region(res->start,
-					res->end - res->start + 1);
+		release_mem_region(res->start, resource_size(res));
 
 }