use wxFILE_SEP_PATH instead of ':' separator for wxMac

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@12227 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/dirctrlg.cpp

@@ -607,7 +607,7 @@ void wxGenericDirCtrl::SetupSections()
         break ;
 
       wxString name = wxMacFSSpec2MacFilename( &volume ) ;
-      AddSection(name+":", name, 0);
+      AddSection(name + wxFILE_SEP_PATH, name, 0);
     }
 #else
   AddSection(wxT("/"), _("The Computer"), 0);