Add a few assertions to be more explicit about the runtime behaviour
after the previous patch: get_vhost_net() is non-null after
net_vhost_user_init().
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>