fdo#59881 - sdremote: revert un-necessary locking change.

Change-Id: Id455dd87f01bbea0c5a4ae26734c0aba5699ac71
(cherry picked from commit ab8e3757)
Signed-off-by: Thorsten Behrens <tbehrens@suse.com>

slideshow/source/engine/slideshowimpl.cxx

@@ -2131,7 +2131,7 @@ sal_Bool SlideShowImpl::update( double & nNextTimeout )
 
 void SlideShowImpl::notifySlideTransitionEnded( bool bPaintSlide )
 {
-    osl::ResettableMutexGuard guard( m_aMutex );
+    osl::MutexGuard const guard( m_aMutex );
 
     OSL_ENSURE( !isDisposed(), "### already disposed!" );
     OSL_ENSURE( mpCurrentSlide,
@@ -2144,10 +2144,6 @@ void SlideShowImpl::notifySlideTransitionEnded( bool bPaintSlide )
         // the chance to register SlideStartEvents
         const bool bBackgroundLayerRendered( !bPaintSlide );
         mpCurrentSlide->show( bBackgroundLayerRendered );
-
-        uno::Reference<presentation::XSlideShow> xThis(
-                static_cast< presentation::XSlideShow * >( this ), uno::UNO_QUERY_THROW );
-        guard.reset(); // unlock
         maEventMultiplexer.notifySlideStartEvent();
     }
 }