i40e: properly add VF MAC addresses

The code that added new MAC addresses from the VFs did not, in
fact, work. Due to inverse logic, the only addresses that could
be added were addresses that already had been added.

Change-Id: Idce9169bd2f36e2c5ee10b130587a65705465d31
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>