gpio: ath79: remove platform_set_drvdata() + cleanup probe

The platform_set_drvdata() call is only useful if we need to retrieve back
the private information.
Since the driver doesn't do that, it's not useful to have it.

If this is removed, we can also just do a direct return on
devm_gpiochip_add_data(). We don't need to print that this call failed as
there are other ways to log/see this during probe.
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-ath79.c

@@ -234,7 +234,6 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
 	if (!ctrl)
 		return -ENOMEM;
-	platform_set_drvdata(pdev, ctrl);
 
 	if (np) {
 		err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
@@ -290,13 +289,7 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 		girq->handler = handle_simple_irq;
 	}
 
-	err = devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
-	if (err) {
-		dev_err(dev,
-			"cannot add AR71xx GPIO chip, error=%d", err);
-		return err;
-	}
-	return 0;
+	return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
 }
 
 static struct platform_driver ath79_gpio_driver = {