While the documentation states that ifname MAC addresses must be
lower case, we silently accept upper case ones and fail later on
when udev doesn't rename the device.
Instead of adding sanity checking on the MAC address just convert
it to lower case and remove the requirement completely.
ifname=<interface>:<MAC>
Assign network device name <interface> (ie eth0) to the NIC
with MAC <MAC>.
Note that if you use this option you *must* specify an ifname=
argument for all interfaces used in ip= or fcoe= arguments
Harald Hoyer