CID#1326472, CID#1326473, CID#1326474 use try/finalize

Coverity requires that closeable objects (use of new) call .close(),

git commit 5a29db7a
implemented a series of .close etc calls, update to
use a single try{}finalize{} instead.

Change-Id: Iadc9de13d6a0af4b0aaca2dfdd0e2d0940a5223d
Reviewed-on: https://gerrit.libreoffice.org/19807Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>