PCI: rockchip: Check for pci_scan_root_bus_bridge() failure correctly

pci_scan_root_bus_bridge() returns zero for success, or a negative errno.
A typo in ae13cb9b1926 ("PCI: rockchip: Convert PCI scan API to
pci_scan_root_bus_bridge()") treated zero as a failure.

Fix the typo.

Fixes: ae13cb9b1926 ("PCI: rockchip: Convert PCI scan API to pci_scan_root_bus_bridge()")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/host/pcie-rockchip.c

@@ -1483,7 +1483,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 	bridge->swizzle_irq = pci_common_swizzle;
 
 	err = pci_scan_root_bus_bridge(bridge);
-	if (!err)
+	if (err < 0)
 		goto err_free_res;
 
 	bus = bridge->bus;