PCI: exynos: 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.

Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>

drivers/pci/dwc/pci-exynos.c

@@ -605,9 +605,9 @@ static int __init exynos_add_pcie_port(struct exynos_pcie *ep,
 	int ret;
 
 	pp->irq = platform_get_irq(pdev, 1);
-	if (!pp->irq) {
+	if (pp->irq < 0) {
 		dev_err(dev, "failed to get irq\n");
-		return -ENODEV;
+		return pp->irq;
 	}
 	ret = devm_request_irq(dev, pp->irq, exynos_pcie_irq_handler,
 				IRQF_SHARED, "exynos-pcie", ep);
@@ -618,9 +618,9 @@ static int __init exynos_add_pcie_port(struct exynos_pcie *ep,
 
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		pp->msi_irq = platform_get_irq(pdev, 0);
-		if (!pp->msi_irq) {
+		if (pp->msi_irq < 0) {
 			dev_err(dev, "failed to get msi irq\n");
-			return -ENODEV;
+			return pp->msi_irq;
 		}
 
 		ret = devm_request_irq(dev, pp->msi_irq,