Documentation: drm: Use '->' when describing access through pointers.

The documentation is trying to describe accessing a field through a
pointer, but it is using '-<' instead of '->'. Fix that.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --cc Documentation/DocBook/drm.tmpl
Simple merge