gpio: dwapb: Don't shadow error code of gpiochip_lock_as_irq()

gpiochip_lock_as_irq() may return a few error codes,
do not shadow them by -EINVAL and let caller to decide.

No functional change intended.

Cc: Hoan Tran <hotran@apm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -255,11 +255,13 @@ static int dwapb_irq_reqres(struct irq_data *d)
 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
 	struct dwapb_gpio *gpio = igc->private;
 	struct gpio_chip *gc = &gpio->ports[0].gc;
+	int ret;
 
-	if (gpiochip_lock_as_irq(gc, irqd_to_hwirq(d))) {
+	ret = gpiochip_lock_as_irq(gc, irqd_to_hwirq(d));
+	if (ret) {
 		dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n",
 			irqd_to_hwirq(d));
-		return -EINVAL;
+		return ret;
 	}
 	return 0;
 }