iavf: Fix VLAN feature flags after VFR

When a VF goes through a reset, it's possible for the VF's feature set
to change. For example it may lose the VIRTCHNL_VF_OFFLOAD_VLAN
capability after VF reset. Unfortunately, the driver doesn't correctly
deal with this situation and errors are seen from downing/upping the
interface and/or moving the interface in/out of a network namespace.

When setting the interface down/up we see the following errors after the
VIRTCHNL_VF_OFFLOAD_VLAN capability was taken away from the VF:

ice 0000:51:00.1: VF 1 failed opcode 12, retval: -64 iavf 0000:51:09.1:
Failed to add VLAN filter, error IAVF_NOT_SUPPORTED ice 0000:51:00.1: VF
1 failed opcode 13, retval: -64 iavf 0000:51:09.1: Failed to delete VLAN
filter, error IAVF_NOT_SUPPORTED

These add/delete errors are happening because the VLAN filters are
tracked internally to the driver and regardless of the VLAN_ALLOWED()
setting the driver tries to delete/re-add them over virtchnl.

Fix the delete failure by making sure to delete any VLAN filter tracking
in the driver when a removal request is made, while preventing the
virtchnl request.  This makes it so the driver's VLAN list is up to date
and the errors are

Fix the add failure by making sure the check for VLAN_ALLOWED() during
reset is done after the VF receives its capability list from the PF via
VIRTCHNL_OP_GET_VF_RESOURCES. If VLAN functionality is not allowed, then
prevent requesting re-adding the filters over virtchnl.

When moving the interface into a network namespace we see the following
errors after the VIRTCHNL_VF_OFFLOAD_VLAN capability was taken away from
the VF:

iavf 0000:51:09.1 enp81s0f1v1: NIC Link is Up Speed is 25 Gbps Full Duplex
iavf 0000:51:09.1 temp_27: renamed from enp81s0f1v1
iavf 0000:51:09.1 mgmt: renamed from temp_27
iavf 0000:51:09.1 dev27: set_features() failed (-22); wanted 0x020190001fd54833, left 0x020190001fd54bb3

These errors are happening because we aren't correctly updating the
netdev capabilities and dealing with ndo_fix_features() and
ndo_set_features() correctly.

Fix this by only reporting errors in the driver's ndo_set_features()
callback when VIRTCHNL_VF_OFFLOAD_VLAN is not allowed and any attempt to
enable the VLAN features is made. Also, make sure to disable VLAN
insertion, filtering, and stripping since the VIRTCHNL_VF_OFFLOAD_VLAN
flag applies to all of them and not just VLAN stripping.

Also, after we process the capabilities in the VF reset path, make sure
to call netdev_update_features() in case the capabilities have changed
in order to update the netdev's feature set to match the VF's actual
capabilities.

Lastly, make sure to always report success on VLAN filter delete when
VIRTCHNL_VF_OFFLOAD_VLAN is not supported. The changed flow in
iavf_del_vlans() allows the stack to delete previosly existing VLAN
filters even if VLAN filtering is not allowed. This makes it so the VLAN
filter list is up to date.

Fixes: 8774370d

 ("i40e/i40evf: support for VF VLAN tag stripping control")
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>