tdf#125691: use _exit() instead of exit()...

for ExitTimer which is used exclusively for
the case when  OOO_EXIT_POST_STARTUP is set, so
that there is no waiting around for ThreadPool's
threads to get joined.

Setting OOO_EXIT_POST_STARTUP already evades any
proper destruction of objects in the heap, so
using _exit() instead of exit() here does not
make things any worse w.r.t the purpose of this
env var.

Change-Id: Ib4a253d6e1a3fd8593e4a2115a51cf4c10344b3c
Reviewed-on: https://gerrit.libreoffice.org/74016
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
diff --git a/desktop/source/app/app.cxx b/desktop/source/app/app.cxx
index bda1df9..0867f6b 100644
--- a/desktop/source/app/app.cxx
+++ b/desktop/source/app/app.cxx
@@ -1911,7 +1911,7 @@ class ExitTimer : public Timer
    }
    virtual void Invoke() override
    {
        exit(42);
        _exit(42);
    }
};