-Werror,-Wunused-variable

(cherry-picked from 849482c0ea88c4aa70ec56adfefe7e59b6060950)

Change-Id: I39d15f863f4e1fd585b03bfc5f8854fb66af3b4c
Reviewed-on: https://gerrit.libreoffice.org/7749
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>