Revert "IASS: Correct Buffering of last Slide"

This reverts commit 77eb3f1a76.

Reason for revert:
Better solution in https://gerrit.libreoffice.org/c/core/+/166177
which is 052c668da3

Change-Id: I42248771c993bcd04c2fe368795db4e1fe7a2586
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/166212
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@me.com>

sd/source/ui/slideshow/slideshowimpl.cxx

@@ -500,18 +500,6 @@ void AnimationSlideController::displayCurrentSlide( const Reference< XSlideShow
                 Any(aValue),
                 PropertyState_DIRECT_VALUE);
     }
-    else if (-1 == nNextSlideNumber)
-    {
-        // IASS: next slide does not exist, thus current slide is the last one.
-        // we need to signal to stop Prefetch since else SlideShowImpl *keeps* the
-        // last slide buffered and will just re-use it when asked to update, thus
-        // updates will not work.
-        aProperties.emplace_back( "Prefetch" ,
-                -1,
-                Any(false),
-                PropertyState_DIRECT_VALUE);
-    }
-
     if (bSkipAllMainSequenceEffects)
     {
         // Add one property that prevents the slide transition from being

slideshow/source/engine/slideshowimpl.cxx

@@ -1041,14 +1041,6 @@ public:
                 seq[0] >>= mpSlideShowImpl->mxPrefetchSlide;
                 seq[1] >>= mpSlideShowImpl->mxPrefetchAnimationNode;
             }
-            else // rProperty.Value might be tested to 'bool' and 'false'
-            {
-                // IASS: There is no 'next' slide (last one is displayed),
-                // so end/flush Prefetch since that might still hold the
-                // last slide what would prevent updating/re-creating it
-                mpSlideShowImpl->mxPrefetchSlide.clear();
-                mpSlideShowImpl->mpPrefetchSlide.reset();
-            }
         }
         else if ( rProperty.Name == "SkipAllMainSequenceEffects" )
         {