iio: mxs-lradc: Propagate the real error code on platform_get_irq() failure

No need to return a 'fake' return value on platform_get_irq() failure.

Just return the error code itself instead.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/mxs-lradc.c

@@ -1558,7 +1558,7 @@ static int mxs_lradc_probe(struct platform_device *pdev)
 	for (i = 0; i < of_cfg->irq_count; i++) {
 		lradc->irq[i] = platform_get_irq(pdev, i);
 		if (lradc->irq[i] < 0)
-			return -EINVAL;
+			return lradc->irq[i];
 
 		ret = devm_request_irq(dev, lradc->irq[i],
 					mxs_lradc_handle_irq, 0,