iavf: Fix VF driver counting VLAN 0 filters

VF driver mistakenly counts VLAN 0 filters, when no PF driver
counts them.
Do not count VLAN 0 filters, when VLAN_V2 is engaged.
Counting those filters in, will affect filters size by -1, when
sending batched VLAN addition message.

Fixes: 968996c0 ("iavf: Fix VLAN_V2 addition/rejection")
Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com>
Signed-off-by: Michal Jaron <michalx.jaron@intel.com>
Signed-off-by: Kamil Maziarz <kamil.maziarz@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>