[patch] drm/virtio: checking for NULL instead of IS_ERR

[Gerd Hoffmann]

On Mi, 2015-06-10 at 22:27 +0300, Dan Carpenter wrote:
> virtio_gpu_alloc_object() returns an error pointer, it never returns
> NULL.
> 
> Fixes: dc5698e80cf7 ('Add virtio gpu driver.')
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

Reviewed-by: Gerd Hoffmann <kraxel at redhat.com>