tdf#120703 PVS: make selection type detection more readable

V547 Expression 'Oep <= Osp' is always false.

Some of the conditions in the type detection code weren't reachable.
Also moved the code from class member to static function.

Change-Id: Iaf9dbe8ab15a1970b5cd580cf5d868715a234d02
Reviewed-on: https://gerrit.libreoffice.org/63230
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

accessibility/inc/extended/textwindowaccessibility.hxx

@@ -540,7 +540,6 @@ private:
 
     void handleSelectionChangeNotification();
 
-    ::sal_Int32 getSelectionType(::sal_Int32 nNewFirstPara, ::sal_Int32 nNewFirstPos, ::sal_Int32 nNewLastPara, ::sal_Int32 nNewLastPos);
     void sendEvent(::sal_Int32 start, ::sal_Int32 end, ::sal_Int16 nEventId);
 
     void disposeParagraphs();