This reverts commit cdd4b528.

The manual acquire()/release() is necessary to prevent a double-delete
if the exception is thrown

Change-Id: I5acc0840befba3981e13b084b8d347f8a2766e70
Reviewed-on: https://gerrit.libreoffice.org/43889Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>