Revert "dev: set iflink to 0 for virtual interfaces"

This reverts commit e1622baf.

The side effect of this commit is to add a '@NONE' after each virtual
interface name with a 'ip link'. It may break existing scripts.

Reported-by: Olivier Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>