Set VF MAC and VLAN ID in two different operations

Set VF MAC and VLAN ID in two different operations

This has a benefit of being able to handle error codes for those
operations separately which is useful when drivers allow setting a MAC
address but do not allow setting a VLAN (which is the case with some
SmartNIC DPUs).

Signed-off-by: Dmitrii Shcherbakov <dmitrii.shcherbakov@canonical.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>