coverity#705444 Improper use of negative value
coverity#705444 Improper use of negative value

Change-Id: Ie3b7634e099de5c8b9a4a77daf47c6038dade370
Reviewed-on: https://gerrit.libreoffice.org/2320
Reviewed-by: Caolán McNamara <301f5784f9f6aac04077f24f1e5abc31af69d401@redhat.com>
Tested-by: Caolán McNamara <301f5784f9f6aac04077f24f1e5abc31af69d401@redhat.com>

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core