coverity#735356 Operands don't affect result

Change-Id: Icd54558abb9d28a5439310ac04613222211e3c61
Reviewed-on: https://gerrit.libreoffice.org/8423
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>