mfd: kempld-core: Use resource_size function on resource object

drivers/mfd/kempld-core.c:461:13-16: WARNING: Suspicious code. resource_size is maybe missing with ioport

Generated by: scripts/coccinelle/api/resource_size.cocci
Signed-off-by: NVasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/kempld-core.c

@@ -458,7 +458,7 @@ static int kempld_probe(struct platform_device *pdev)
 		return -EINVAL;
 
 	pld->io_base = devm_ioport_map(dev, ioport->start,
-					ioport->end - ioport->start);
+					resource_size(ioport));
 	if (!pld->io_base)
 		return -ENOMEM;