iavf: send VLAN offloading caps once after VFR

When the user disables rxvlan offloading and then changes the number of
channels, all VLAN ports are unable to receive traffic.

Changing the number of channels triggers a VFR reset. During re-init, when
VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS is received, we do:
1 - set the IAVF_FLAG_SETUP_NETDEV_FEATURES flag
2 - call
    iavf_set_vlan_offload_features(adapter, 0, netdev->features);

The second step sends to the PF the __default__ features, in this case
aq_required |= IAVF_FLAG_AQ_ENABLE_CTAG_VLAN_STRIPPING

While the first step forces the watchdog task to call
netdev_update_features() ->  iavf_set_features() ->
iavf_set_vlan_offload_features(adapter, netdev->features, features).
Since the user disabled the "rxvlan", this sets:
aq_required |= IAVF_FLAG_AQ_DISABLE_CTAG_VLAN_STRIPPING

When we start processing the AQ commands, both flags are enabled. Since we
process DISABLE_XTAG first then ENABLE_XTAG, this results in the PF
enabling the rxvlan offload. This breaks all communications on the VLAN
net devices.

Fix by removing the call to iavf_set_vlan_offload_features() (second
step). Calling netdev_update_features() from watchdog task is enough for
both init and reset paths.

Fixes: 7598f4b4

 ("iavf: Move netdev_update_features() into watchdog task")
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>