This is useful when creating virtual interfaces. Keeps udev from mucking with things it shouldn't, since the default MAC is never seen by udev when specified on the cmd-line during creation. Signed-off-by: Ben Greear <greearb@candelatech.com> [check for feature flag in nl80211 to force drivers to set it] Signed-off-by: Johannes Berg <johannes.berg@intel.com>