PCI: keystone: Fix error handling when "num-viewport" DT property is not populated

Fix error handling when "num-viewport" DT property is not populated.

Fixes: 23284ad6 ("PCI: keystone: Add support for PCIe EP in AM654x Platforms")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org # v5.2+

drivers/pci/controller/dwc/pci-keystone.c

@@ -1354,7 +1354,7 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
 		ret = of_property_read_u32(np, "num-viewport", &num_viewport);
 		if (ret < 0) {
 			dev_err(dev, "unable to read *num-viewport* property\n");
-			return ret;
+			goto err_get_sync;
 		}
 
 		/*