Rename RTL8153 usbnet on Dell system with pathname

Bug: https://bugs.launchpad.net/oem-priority/+bug/1843381

Dell has a feature called MAC address passthrough1 that would force USB ethernet adapters to be assigned with a predefined MAC address stored in BIOS or so. This feature has been landed on the mainline kernel in driver r81522. Thus whenever a r8152 managed device is plugged into Dell devices with MAC address passthrough enabled, this driver will set NIC MAC to a predefined one.

And some Dell devices have already one built-in r8152 NIC port. On these devices, when a second r8152 NIC is plugged in, a Debian originated udev rules file 73-usb-net-by-mac.rules3 will invoke udev built-in command net_id to give a persistent name, and that will be based on MAC address. However, since the system has already initialized the built-in r8152 NIC with that name, renaming the second interface with this name will always fail.

Since it is not possible to assign a persistent name based on MAC address, let's take a step back to use the pathname instead.

Signed-off-by: ChunKim, TeN cktenn@gmail.com