Found by scanbuild.

Change-Id: Ie46c056327747bbcb3a9eb0890cf74be7179ea24
Reviewed-on: https://gerrit.libreoffice.org/20257Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: jan iversen <jani@documentfoundation.org>
Reviewed-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>