rtc: rtc-coh901331: use devm_ioremap_resource()

Use devm_ioremap_resource() in order to make the code simpler, and
remove redundant return value check of platform_get_resource() because
the value is checked by devm_ioremap_resource().
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-coh901331.c

@@ -43,8 +43,6 @@
 struct coh901331_port {
 	struct rtc_device *rtc;
 	struct clk *clk;
-	u32 phybase;
-	u32 physize;
 	void __iomem *virtbase;
 	int irq;
 #ifdef CONFIG_PM_SLEEP
@@ -173,19 +171,9 @@ static int __init coh901331_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -ENOENT;
-
-	rtap->phybase = res->start;
-	rtap->physize = resource_size(res);
-
-	if (devm_request_mem_region(&pdev->dev, rtap->phybase, rtap->physize,
-				    "rtc-coh901331") == NULL)
-		return -EBUSY;
-
-	rtap->virtbase = devm_ioremap(&pdev->dev, rtap->phybase, rtap->physize);
-	if (!rtap->virtbase)
-		return -ENOMEM;
+	rtap->virtbase  = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(rtap->virtbase))
+		return PTR_ERR(rtap->virtbase);
 
 	rtap->irq = platform_get_irq(pdev, 0);
 	if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0,