rcutorture: make use of the helper function kthread_run_on_cpu()

Replace kthread_create_on_node/kthread_bind/wake_up_process() with
kthread_run_on_cpu() to simplify the code.

Link: https://lkml.kernel.org/r/20211022025711.3673-5-caihuoqing@baidu.com
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Cc: Bernard Metzler <bmt@zurich.ibm.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/rcu/rcutorture.c

@@ -1992,9 +1992,8 @@ static int rcutorture_booster_init(unsigned int cpu)
 	mutex_lock(&boost_mutex);
 	rcu_torture_disable_rt_throttle();
 	VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
-	boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
-						  cpu_to_node(cpu),
-						  "rcu_torture_boost");
+	boost_tasks[cpu] = kthread_run_on_cpu(rcu_torture_boost, NULL,
+					      cpu, "rcu_torture_boost_%u");
 	if (IS_ERR(boost_tasks[cpu])) {
 		retval = PTR_ERR(boost_tasks[cpu]);
 		VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
@@ -2003,8 +2002,6 @@ static int rcutorture_booster_init(unsigned int cpu)
 		mutex_unlock(&boost_mutex);
 		return retval;
 	}
-	kthread_bind(boost_tasks[cpu], cpu);
-	wake_up_process(boost_tasks[cpu]);
 	mutex_unlock(&boost_mutex);
 	return 0;
 }