CreateTextHelp() itself does the check on nullptr. No need for the
callers to do the same.

Change-Id: Ib57f3b818235a4e0fb302dda3562c9c8a29a4e54
Reviewed-on: https://gerrit.libreoffice.org/30919Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>