watchdog: pic32-dmt: Fix return value check in pic32_dmt_probe()

In case of error, the function devm_kzalloc() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should
be replaced with NULL test.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/pic32-dmt.c

@@ -176,8 +176,8 @@ static int pic32_dmt_probe(struct platform_device *pdev)
 	struct watchdog_device *wdd = &pic32_dmt_wdd;
 
 	dmt = devm_kzalloc(&pdev->dev, sizeof(*dmt), GFP_KERNEL);
-	if (IS_ERR(dmt))
+	if (!dmt)
-		return PTR_ERR(dmt);
+		return -ENOMEM;
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dmt->regs = devm_ioremap_resource(&pdev->dev, mem);