[taskdistribution] apply some fixes

- Use unrestricted _edit method on reportTaskStatus - restrictedTraverse applies security anyway
- Remove some useless code
- Fix TypeError: stopUnitTest() takes exactly 3 arguments (4 given)

product/ERP5/Document/ERP5ProjectUnitTestDistributor.py

@@ -441,9 +441,7 @@ class ERP5ProjectUnitTestDistributor(XMLObject):
     """
     LOG('ERP5ProjectUnitTestDistributor.stop_unit_test', 0, test_path)
     portal = self.getPortalObject()
-    test_result = portal.unrestrictedTraverse(test_path)
-    test_suite_title = test_result.getTitle()
-    return portal.portal_task_distribution.stopUnitTest(self,test_path,status_dict)
+    return portal.portal_task_distribution.stopUnitTest(test_path, status_dict)
 
   security.declarePublic("generateConfiguration")
   def generateConfiguration(self, test_suite_title, batch_mode=0):

product/ERP5/Tool/TaskDistributionTool.py

@@ -294,7 +294,7 @@ class TaskDistributionTool(BaseTool):
     test_result = portal.restrictedTraverse(test_result_path)
     node = self._getTestResultNode(test_result, node_title)
     assert node is not None
-    node.edit(cmdline=status_dict['command'],
+    node._edit(cmdline=status_dict['command'],
               stdout=status_dict['stdout'], stderr=status_dict['stderr'])
 
   security.declarePublic('isTaskAlive')