Input: imx6ul_tsc - check for negative return value

We should check for negative values returned by platform_get_irq().

Signed-off-by: Fabio Estevam <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/touchscreen/imx6ul_tsc.c

···
 	}
 
 	adc_irq = platform_get_irq(pdev, 1);
-	if (adc_irq <= 0) {
+	if (adc_irq < 0) {
 		dev_err(&pdev->dev, "no adc irq resource?\n");
 		return adc_irq;
 	}