InteractionWorkflow.py: code clean up / simplified.

product/ERP5Workflow/Document/InteractionWorkflow.py

@@ -158,9 +158,7 @@ class InteractionWorkflow(IdAsReferenceMixin("", "prefix"), Workflow):
     is supported in the current state.
     '''
     tdef = self._getOb('interaction_' + tid)
-    if tdef is not None and self._checkTransitionGuard(tdef, ob):
-      return 1
-    return 0
+    return tdef is not None and self._checkTransitionGuard(tdef, ob)
 
   def _checkTransitionGuard(self, tdef, document, **kw):
     if tdef.temporary_document_disallowed: