hwmon: (gpd-fan) Fix return value when platform_get_resource() fails

When platform_get_resource() fails it returns NULL and not an error
pointer, accordingly change the error handling.

Fixes: 0ab88e2 ("hwmon: add GPD devices sensor driver")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20251010204359.94300-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Author: harshimogalapalli

drivers/hwmon/gpd-fan.c

@@ -615,8 +615,8 @@ static int gpd_fan_probe(struct platform_device *pdev)
 	const struct device *hwdev;
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
-	if (IS_ERR(res))
-		return dev_err_probe(dev, PTR_ERR(res),
+	if (!res)
+		return dev_err_probe(dev, -EINVAL,
 				     "Failed to get platform resource\n");
 
 	region = devm_request_region(dev, res->start,