PCI: rockchip-ep: Fix error code in rockchip_pcie_ep_init_ob_mem()

Return -ENOMEM if pci_epc_mem_alloc_addr() fails.  Don't return success.

Link: https://lore.kernel.org/r/Z014ylYz_xrrgI4W@stanley.mountain
Fixes: 9456480 ("PCI: rockchip-ep: Refactor rockchip_pcie_ep_probe() memory allocations")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>

drivers/pci/controller/pcie-rockchip-ep.c

@@ -788,6 +788,7 @@ static int rockchip_pcie_ep_init_ob_mem(struct rockchip_pcie_ep *ep)
 						  SZ_1M);
 	if (!ep->irq_cpu_addr) {
 		dev_err(dev, "failed to reserve memory space for MSI\n");
+		err = -ENOMEM;
 		goto err_epc_mem_exit;
 	}