And fix some const-incorrect-ness while at it.

Change-Id: I0314c8e5b73f1a7edce040b2a57fbc5d1081d70c
Reviewed-on: https://gerrit.libreoffice.org/20815Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>