dragonball: Vhost-user base code not supported INFLIGHT_SHMFD

[justxuewei]

A workaround for vhost-user-net unit tests.

let handler = thread::spawn(move || {
    let mut slave = connect_slave(device_socket).unwrap();
    create_vhost_user_net_slave(&mut slave);
    let mut pfeatures = VhostUserProtocolFeatures::all();
    // ++++++
    pfeatures -= VhostUserProtocolFeatures::INFLIGHT_SHMFD;
    negotiate_slave(&mut slave, pfeatures, true, 1);
});

[ZizhengBian]

I will work for this later.

[adamqqqplay]

vhost-user-blk also need this feature, but we temporarily disabled it in #8632.