[PATCH] Fix use after free in get_capset_info callback

[Markus Elfring]

> If a response to virtio_gpu_cmd_get_capset_info takes longer than
> five seconds to return, the callback will access freed kernel memory
> in vg->capsets.

* Can another imperative wording become helpful for the change description?

* How do you think about to mention the proposed addition of a spin lock
  and a null pointer check?

* Would you like to add the tag “Fixes” to the commit message?

Regards,
Markus