qwayland-xcomposite-glx: Fix qwaylandintegration_p.h name

* it was made private in
  commit b6713ec4262c05f7d103bc3b75ab81aedc690853
  Author: Jorgen Lind <jorgen.lind@digia.com>
  Date:   Wed Dec 18 07:59:53 2013 +0100

    Make classes in client private

  and qwayland-xcomposite-glx wasn't adapted to it

Change-Id: If0c43dce6bfa8af85c5b8a98ff4ead799f29a194
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>