serial: mxs-auart: Check for platform_get_irq() error

We should check whether platform_get_irq() failed, and in the case of error
this needs to be propagated.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/mxs-auart.c

@@ -1265,6 +1265,9 @@ static int mxs_auart_probe(struct platform_device *pdev)
 	s->mctrl_prev = 0;
 
 	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
 	s->port.irq = irq;
 	ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0,
 			       dev_name(&pdev->dev), s);