virtio-net: Remove more stack DMA

VLAN and MQ control was doing DMA from the stack.  Fix it.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>