coverity#1000658 Missing break in switch, assuming its intentional

Change-Id: Id208942e98c8b8fc685aa77c3c11468ed2af832d

sfx2/source/control/thumbnailview.cxx

@@ -621,6 +621,7 @@ void ThumbnailView::KeyInput( const KeyEvent& rKEvt )
                 if ( bFoundLast )
                     OnItemDblClicked( mFilteredItemList[nLastPos] );
             }
+            //fall-through
         default:
             Control::KeyInput( rKEvt );
     }