gpio-charger: Fix checking return value of request_any_context_irq

request_any_context_irq() returns a negative value on failure.
On success, it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/gpio-charger.c

@@ -127,7 +127,7 @@ static int __devinit gpio_charger_probe(struct platform_device *pdev)
 		ret = request_any_context_irq(irq, gpio_charger_irq,
 				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 				dev_name(&pdev->dev), charger);
-		if (ret)
+		if (ret < 0)
 			dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
 		else
 			gpio_charger->irq = irq;