Revert "st/dri: Fix dangling pointer to a destroyed dri_drawable"
This reverts commit dab02dea.
It causes crashes of qtcreator and firefox.
Fixes: dab02dea "st/dri: Fix dangling pointer to a destroyed dri_drawable"
Cc: 18.0 18.1 <mesa-stable@lists.freedesktop.org>
(cherry picked from commit 4559aefb)