tools/virtio: fix virtio_test execution

virtio_test hangs on __vring_new_virtqueue() because `vqs_list_lock`
is not initialized.

Let's initialize it in vdev_info_init().

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20220118150631.167015-1-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

tools/virtio/virtio_test.c

@@ -130,6 +130,7 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
 	memset(dev, 0, sizeof *dev);
 	dev->vdev.features = features;
 	INIT_LIST_HEAD(&dev->vdev.vqs);
+	spin_lock_init(&dev->vdev.vqs_list_lock);
 	dev->buf_size = 1024;
 	dev->buf = malloc(dev->buf_size);
 	assert(dev->buf);