pata_imx: 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.

Also, change the error condition to irq < 0, so that only negative values
are treated as errors.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/pata_imx.c b/drivers/ata/pata_imx.c
index 50e2cf2..121c748 100644
--- a/drivers/ata/pata_imx.c
+++ b/drivers/ata/pata_imx.c
@@ -100,8 +100,8 @@
 	int ret;
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0)
-		return -EINVAL;
+	if (irq < 0)
+		return irq;
 
 	priv = devm_kzalloc(&pdev->dev,
 				sizeof(struct pata_imx_priv), GFP_KERNEL);