MINOR: tasks: Don't set the TASK_RUNNING flag when adding in the tasklet list.

Now that TASK_QUEUED is enforced, there's no need to set TASK_RUNNING when
removing the task from the runqueue to add it to the tasklet list. The flag
will only be set right before we run the task.

src/task.c

@@ -342,9 +342,6 @@ void process_runnable_tasks()
 		}
 #endif
 
-		/* Make sure nobody re-adds the task in the runqueue */
-		_HA_ATOMIC_OR(&t->state, TASK_RUNNING);
-
 		/* And add it to the local task list */
 		task_insert_into_tasklet_list(t);
 	}