[PATCH 3/4] drm/virtio: simplify cursor updates

[Gerd Hoffmann]

> Even nicer would be to add the fence using
> drm_atomic_set_fence_for_plane() in the prepare_fb hook. Assuming this
> isn't necessary for correctness (but then I kinda have questions about
> races and stuff).

I'll have a look.  Maybe this way I can drop struct
virtio_gpu_framebuffer (where the fence is the only
thing beside struct drm_framebuffer).

cheers,
  Gerd