gpio: ftgpio010: Do not check for 0 return after calling platform_get_irq()

Since commit a85a6c86 ("driver core: platform: Clarify that IRQ 0
is invalid"), there is no possible for platform_get_irq() to return 0.

And the return value of platform_get_irq() is more sensible
to show the error reason.
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-ftgpio010.c

@@ -250,8 +250,8 @@ static int ftgpio_gpio_probe(struct platform_device *pdev)
 		return PTR_ERR(g->base);
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0)
-		return irq ? irq : -EINVAL;
+	if (irq < 0)
+		return irq;
 
 	g->clk = devm_clk_get(dev, NULL);
 	if (!IS_ERR(g->clk)) {