watchdog: rt2880_wdt: fix return value check in rt288x_wdt_probe()

In case of error, the function devm_request_and_ioremap() returns NULL
pointer not ERR_PTR(). Fix it by using devm_ioremap_resource() instead
of devm_request_and_ioremap().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

drivers/watchdog/rt2880_wdt.c

@@ -144,7 +144,7 @@ static int rt288x_wdt_probe(struct platform_device *pdev)
 	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	rt288x_wdt_base = devm_request_and_ioremap(&pdev->dev, res);
+	rt288x_wdt_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(rt288x_wdt_base))
 		return PTR_ERR(rt288x_wdt_base);