PCI: altera: Fix platform_get_irq() error handling

platform_get_irq() returns a negative number on failure, so adjust the
logic to detect such condition and propagate the real error value on
failure.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Ley Foon Tan <lftan@altera.com>

drivers/pci/host/pcie-altera-msi.c

@@ -265,9 +265,9 @@ static int altera_msi_probe(struct platform_device *pdev)
 		return ret;
 
 	msi->irq = platform_get_irq(pdev, 0);
-	if (msi->irq <= 0) {
+	if (msi->irq < 0) {
 		dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq);
-		ret = -ENODEV;
+		ret = msi->irq;
 		goto err;
 	}
 

drivers/pci/host/pcie-altera.c

@@ -558,9 +558,9 @@ static int altera_pcie_parse_dt(struct altera_pcie *pcie)
 
 	/* setup IRQ */
 	pcie->irq = platform_get_irq(pdev, 0);
-	if (pcie->irq <= 0) {
+	if (pcie->irq < 0) {
 		dev_err(dev, "failed to get IRQ: %d\n", pcie->irq);
-		return -EINVAL;
+		return pcie->irq;
 	}
 
 	irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);