i40e: correctly program filters for VFs

MAC filters for VFs were being programmed with 0 for the VLAN value when
there was no VLAN assigned. This is incorrect and actually assigns the
VF to VLAN 0. Instead, we must use -1 to indicate that no VLAN is in
use. This change programs the filters correctly and gets rid of a bogus
error message when setting a port VLAN on an active VF.

Change-ID: Ica9a9906d768405377ff3308e27f7d0b5b2ea96e
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>