[PATCH] cpu/hotplug: simplify access percpu cpuhp_state

[Yuan ZhaoXiong <yuanzhaoxiong@baidu.com>]

It is unnecessary to invoke per_cpu_ptr() function everytime to access
percpu cpuhp_state and use the variable st instead.

Signed-off-by: Yuan ZhaoXiong <yuanzhaoxiong@baidu.com>
---
 kernel/cpu.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index e538518..2942cb4 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -961,7 +961,7 @@ static int takedown_cpu(unsigned int cpu)
 	int err;
 
 	/* Park the smpboot threads */
-	kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread);
+	kthread_park(st->thread);
 
 	/*
 	 * Prevent irq alloc/free while the dying cpu reorganizes the
@@ -977,7 +977,7 @@ static int takedown_cpu(unsigned int cpu)
 		/* CPU refused to die */
 		irq_unlock_sparse();
 		/* Unpark the hotplug thread so we can rollback there */
-		kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread);
+		kthread_unpark(st->thread);
 		return err;
 	}
 	BUG_ON(cpu_online(cpu));
-- 
1.7.1