pinctrl: imx1: fix return value check in imx1_pinctrl_core_probe()

In case of error, the function devm_ioremap_nocache() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-imx1-core.c

@@ -615,8 +615,8 @@ int imx1_pinctrl_core_probe(struct platform_device *pdev,
 
 	ipctl->base = devm_ioremap_nocache(&pdev->dev, res->start,
 			resource_size(res));
-	if (IS_ERR(ipctl->base))
-		return PTR_ERR(ipctl->base);
+	if (!ipctl->base)
+		return -ENOMEM;
 
 	pctl_desc = &imx1_pinctrl_desc;
 	pctl_desc->name = dev_name(&pdev->dev);