[PATCH] drm: document DRM_IOCTL_MODE_GETFB2

[Daniel Stone]

On Tue, 9 Nov 2021 at 08:56, Simon Ser <contact at emersion.fr> wrote:
> There are a few details specific to the GETFB2 IOCTL.
>
> It's not immediately clear how user-space should check for the
> number of planes. Suggest using the pitches field.

In fairness it is perfectly clear, it's just that I never considered
calling it without master/admin because why would you ever do that?
Anyway, the docs look correct and the more the better for sure, so
this is:
Acked-by: Daniel Stone <daniels at collabora.com>