usb: dwc2: pci: Fix an error code in probe

We added some error handling to this function but forgot to set the
error code on this path.

Fixes: ecd29dab ("usb: dwc2: pci: Handle error cleanup in probe")
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/pci.c

@@ -120,6 +120,7 @@ static int dwc2_pci_probe(struct pci_dev *pci,
 	dwc2 = platform_device_alloc("dwc2", PLATFORM_DEVID_AUTO);
 	if (!dwc2) {
 		dev_err(dev, "couldn't allocate dwc2 device\n");
+		ret = -ENOMEM;
 		goto err;
 	}