usbnet: fix failure handling in usbnet_probe

If register_netdev returns failure, the dev->interrupt and
its transfer buffer should be released, so just fix it.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index ca6fd80..2d927fb 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1444,7 +1444,7 @@
 
 	status = register_netdev (net);
 	if (status)
-		goto out3;
+		goto out4;
 	netif_info(dev, probe, dev->net,
 		   "register '%s' at usb-%s-%s, %s, %pM\n",
 		   udev->dev.driver->name,
@@ -1462,6 +1462,8 @@
 
 	return 0;
 
+out4:
+	usb_free_urb(dev->interrupt);
 out3:
 	if (info->unbind)
 		info->unbind (dev, udev);