Matching the MAC of the tap interface on the hypervisor
to the MAC that the VM will actually use to send traffic
through the tap causes the following error messages:
brq9e974900-cd: received packet on tapa8a6ce4a-e8 with
own address as source address
This is triggering a warning because there are now two
forwarding entries on the bridge, a static one from the
tap device, and a learned one from the packets received.
Due to the presence of a static MAC entry, this will break
things like allowed_address_pair use cases that allow a MAC
to be used by multiple ports.
This patch removes all of the logic to set the MAC
address on the TAP device because it didn't serve any
other purpose than easy to correlate output from
ip link show commands and neutron port MAC addresses.
TAP devices will now just get whatever MAC address the kernel
selects for them.