rculist: fix borked __list_for_each_rcu() macro

This restores parentheses blance.

Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index f31ef61..70d3ba5 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -244,7 +244,7 @@
 #define __list_for_each_rcu(pos, head) \
 	for (pos = rcu_dereference_raw(list_next_rcu(head)); \
 		pos != (head); \
-		pos = rcu_dereference_raw(list_next_rcu((pos)))
+		pos = rcu_dereference_raw(list_next_rcu(pos)))
 
 /**
  * list_for_each_entry_rcu	-	iterate over rcu list of given type