The igb driver currently requires a VF interface to have a non-zero MAC
address, but the associated PF is giving the VF an all zeros MAC address
when one is not administratively assigned. The driver should check for
this case and generate a random address, similar to how the linux igbvf
driver does.

Submitted by: skoumjian@juniper.net (Scott Koumjian)
MFH: 2 weeks
Differential Revision: https://reviews.freebsd.org/D8399