adding wxFALLTHROUGH where until now we had comments, allows for code-analysis support

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76399 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/treectlg.cpp

@@ -3122,7 +3122,7 @@ void wxGenericTreeCtrl::OnChar( wxKeyEvent &event )
                 ExpandAllChildren(m_current);
                 break;
             }
-            //else: fall through to Collapse() it
+            wxFALLTHROUGH;//else: fall through to Collapse() it
 
         case '-':
         case WXK_SUBTRACT:
@@ -3236,7 +3236,7 @@ void wxGenericTreeCtrl::OnChar( wxKeyEvent &event )
             //else: don't try to expand hidden root item (which can be the
             //      current one when the tree is empty)
 
-            // fall through
+            wxFALLTHROUGH;
 
         case WXK_DOWN:
             {