src/sched_policies/heft.c: Fix a bug that caused a handle to be converted twice in some cases.

Thanks to Andra for reporting this bug !

src/sched_policies/heft.c

@@ -366,13 +366,11 @@ static int push_conversion_tasks(struct starpu_task *task, unsigned int workerid
 		conversion_task->execute_on_a_specific_worker = 1;
 		conversion_task->workerid = workerid;
 		conversion_task->mf_skip = 1;
+		handle->mf_node = node;
 		ret = _starpu_task_submit_conversion_task(conversion_task, workerid);
 		STARPU_ASSERT(ret == 0);
 	}
 
-	for (i = 0; i < task->cl->nbuffers; i++)
-		task->handles[i]->mf_node = node;
-
 	task->execute_on_a_specific_worker = 1;
 	task->workerid = workerid;
 	task->mf_skip= 1;