workqueue/hotplug: remove the workaround in rebind_workers()

Since the cpu/hotplug refactoring, DOWN_FAILED is never called without
preceding DOWN_PREPARE making the workaround unnecessary.  Remove it.
Signed-off-by: NLai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

kernel/workqueue.c

@@ -4589,16 +4589,6 @@ static void rebind_workers(struct worker_pool *pool)
 
 	spin_lock_irq(&pool->lock);
 
-	/*
-	 * XXX: CPU hotplug notifiers are weird and can call DOWN_FAILED
-	 * w/o preceding DOWN_PREPARE.  Work around it.  CPU hotplug is
-	 * being reworked and this can go away in time.
-	 */
-	if (!(pool->flags & POOL_DISASSOCIATED)) {
-		spin_unlock_irq(&pool->lock);
-		return;
-	}
-
 	pool->flags &= ~POOL_DISASSOCIATED;
 
 	for_each_pool_worker(worker, pool) {