Change MAC address only if needed
Change MAC address only if needed

Some virtual interfaces have a different MAC address from their real
interfaces and their drivers disallow us to change it. In this case
we don't need to change the MAC address anyway.

With this we can avoid errors like 'RTNETLINK answers: Invalid argument'.

tymiles003/create_ap,Delvison/create_ap,wsxarcher/create_ap,ekuri/create_ap,agusedy/create_ap,eipiminus1/create_ap,ninjasphere/create_ap,oblique/create_ap,hashken/create_ap,ishan-marikar/create_ap,everhopingandwaiting/create_ap,UlrichAbiguime/create_ap