coverity#1210177 Uninitialized pointer field

Change-Id: If4e8ddfa0a4dcb9875ce82fc82d196ff3dbd9657
(cherry picked from commit f670aaaabf23f13ae5ebf61ba61824794137c597)
Reviewed-on: https://gerrit.libreoffice.org/9201
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>