worker_thread: don't play with signals

worker_thread() doesn't need to "Block and flush all signals", this was
already done by its caller, kthread().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/workqueue.c

@@ -290,18 +290,11 @@ static int worker_thread(void *__cwq)
 	struct cpu_workqueue_struct *cwq = __cwq;
 	DEFINE_WAIT(wait);
 	struct k_sigaction sa;
-	sigset_t blocked;
 
 	if (!cwq->wq->freezeable)
 		current->flags |= PF_NOFREEZE;
 
 	set_user_nice(current, -5);
-
-	/* Block and flush all signals */
-	sigfillset(&blocked);
-	sigprocmask(SIG_BLOCK, &blocked, NULL);
-	flush_signals(current);
-
 	/*
 	 * We inherited MPOL_INTERLEAVE from the booting kernel.
 	 * Set MPOL_DEFAULT to insure node local allocations.