vsock/virtio: enable VQs early on probe

virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after probe returns, but virtio-vsock
driver uses VQs in the probe function to fill rx and event VQs
with new buffers.

Let's fix this, calling virtio_device_ready() before using VQs
in the probe function.

Fixes: 0ea9e1d ("VSOCK: Introduce virtio_transport.ko")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: stefano-garzarella

net/vmw_vsock/virtio_transport.c

@@ -627,6 +627,8 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 
 	vdev->priv = vsock;
 
+	virtio_device_ready(vdev);
+
 	mutex_lock(&vsock->tx_lock);
 	vsock->tx_run = true;
 	mutex_unlock(&vsock->tx_lock);