gpio: loongson-64bit: Fix a less than zero check on an unsigned int struct field

Currently the error check from the call to platform_get_irq is always
false because an unsigned int chip->irq.parents[i] is being used to
to perform the less than zero error check. Fix this by using the int
variable ret to perform the check.

Fixes: 03c146c ("gpio: loongson-64bit: Add support for Loongson-2K0300 SoC")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Yao Zi <ziyao@disroot.org>
Link: https://lore.kernel.org/r/20250909190356.870000-1-colin.i.king@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: ColinIanKing

drivers/gpio/gpio-loongson-64bit.c

@@ -267,10 +267,13 @@ static int loongson_gpio_init_irqchip(struct platform_device *pdev,
 		return -ENOMEM;
 
 	for (i = 0; i < data->intr_num; i++) {
-		chip->irq.parents[i] = platform_get_irq(pdev, i);
-		if (chip->irq.parents[i] < 0)
-			return dev_err_probe(&pdev->dev, chip->irq.parents[i],
+		int ret;
+
+		ret = platform_get_irq(pdev, i);
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret,
 					     "failed to get IRQ %d\n", i);
+		chip->irq.parents[i] = ret;
 	}
 
 	for (i = 0; i < data->intr_num; i++) {