PTR_ERR should be called before its argument is cleared.

Author: Julia Lawall <Julia.Lawall@lip6.fr>

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
expression e,e1;
constant c;
@@

*e = c
... when != e = e1
    when != &e
    when != true IS_ERR(e)
*PTR_ERR(e)
// 

Signed-off-by: Julia Lawall 
Reported-by: Josh Triplett 
Signed-off-by: Paul E. McKenney 
---
 kernel/rcutorture.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
 
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index ed1c72b..a89b381 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -1465,12 +1465,15 @@ rcu_torture_onoff(void *arg)
 static int __cpuinit
 rcu_torture_onoff_init(void)
 {
+	int ret;
+
 	if (onoff_interval <= 0)
 		return 0;
 	onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff");
 	if (IS_ERR(onoff_task)) {
+		ret = PTR_ERR(onoff_task);
 		onoff_task = NULL;
-		return PTR_ERR(onoff_task);
+		return ret;
 	}
 	return 0;
 }