Workflow.py: fix the workflow history may get state id instead of state...

Workflow.py: fix the workflow history may get state id instead of state reference in the execution of action.

product/ERP5Workflow/Document/Workflow.py

@@ -1038,7 +1038,7 @@ class Workflow(IdAsReferenceMixin("", "prefix"), XMLObject):
         value = expr(econtext)
       status[id] = value
 
-    status['comment'] = 'Jump from %r to %r' % (old_state, new_state_id_no_prefix,)
+    status['comment'] = 'Jump from %r to %r' % (self._getOb(old_state).getReference(), new_state_id_no_prefix,)
     status[self.getStateVariable()] = new_state_id_no_prefix
     tool = self.getParent()
     tool.setStatusOf(self.getId(), ob, status)