virtio-net: do not reset vlan filtering at set_features

virtio-net: do not reset vlan filtering at set_features

This function is called after virtio_load, so all vlan configuration is
lost in migration case.

Just allow all the vlan-tagged packets if vlan is not configured, and
trust device reset to clear all filtered vlans.

Fixes: 0b1eaa8803 ("virtio-net: Do not filter VLANs without F_CTRL_VLAN")
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Hawkins Jiawei <yin31149@gmail.com>
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Message-Id: <95af0d013281282f48ad3f47f6ad1ac4ca9e52eb.1690106284.git.yin31149@gmail.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>