...where all but the variants for Android and --enable-headless already did so
(and curiously the DestroySalInstance variants for Android and --enable-headless
already contained code to release the solar mutex).  See the thread at
<http://lists.freedesktop.org/archives/libreoffice/2012-December/042535.html>
"--headless broken with --enable-headless" for further details.

Change-Id: I01be2e237e203a151ea8b1f3adfbcb3e63247cd7