gpio: bcm-kona: Fix return value of bcm_kona_gpio_probe()

Propagate the error code returned by devm_platform_ioremap_resource()
out of probe() instead of overwriting it.

Fixes: 72d8cb7 ("drivers: gpio: bcm-kona: use devm_platform_ioremap_resource()")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-bcm-kona.c

@@ -625,7 +625,7 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev)
 
 	kona_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(kona_gpio->reg_base)) {
-		ret = -ENXIO;
+		ret = PTR_ERR(kona_gpio->reg_base);
 		goto err_irq_domain;
 	}