Fix iterator boundary

Change-Id: I81366dd7f08cf50eb289e742b3923f343ce10f80
Reviewed-on: https://gerrit.libreoffice.org/66409
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

sc/source/ui/Accessibility/AccessibleDocumentPagePreview.cxx

@@ -713,7 +713,7 @@ void ScShapeChildren::FindChanged(ScShapeChildVec& rOld, ScShapeChildVec& rNew)
     ScShapeChildVec::iterator aOldItr = rOld.begin();
     ScShapeChildVec::iterator aOldEnd = rOld.end();
     ScShapeChildVec::const_iterator aNewItr = rNew.begin();
-    ScShapeChildVec::const_iterator aNewEnd = rNew.begin();
+    ScShapeChildVec::const_iterator aNewEnd = rNew.end();
     uno::Reference<XAccessible> xAcc;
     while ((aNewItr != aNewEnd) && (aOldItr != aOldEnd))
     {