i40evf: correctly populate vlan_features

The vlan_features field was correctly being set to the same value as the
netdev features field. However, this was being done before the features
were actually being set up, leaving the vlan_features empty.

Also, after a reset, vlan_features will be incorrectly assigned the
previous netdev feature flags, which can contain VLAN feature bits. This
makes the VLAN code angry and will cause a stack dump.

To fix these issues, set up the netdev features first, then mask out the
VLAN feature bits when assigning vlan_features.

Change-ID: Ib0548869dc83cf6a841cb8697dd94c12359ba4d2
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>