fdo#39440 remove unused variables

This addresses 3 cppcheck "unusedVariable" warnings.

Change-Id: I2bf566458b84f34422cee08a3814ad5b04955e50
Reviewed-on: https://gerrit.libreoffice.org/13460
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>