watchdog: tqmx86: Fix a couple IS_ERR() vs NULL bugs

These functions return NULL on error but we accidentally check
for IS_ERR() instead.

Fixes: e3c21e088f ("watchdog: tqmx86: Add watchdog driver for the IO controller")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/tqmx86_wdt.c

@@ -79,13 +79,13 @@ static int tqmx86_wdt_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
-	if (IS_ERR(res))
-		return PTR_ERR(res);
+	if (!res)
+		return -ENODEV;
 
 	priv->io_base = devm_ioport_map(&pdev->dev, res->start,
 					resource_size(res));
-	if (IS_ERR(priv->io_base))
-		return PTR_ERR(priv->io_base);
+	if (!priv->io_base)
+		return -ENOMEM;
 
 	watchdog_set_drvdata(&priv->wdd, priv);