rcu: Correct the name of a reference in list of RCU papers

Trying to go through the history of RCU (not for the weak
minded) led me to search for a non-existent paper.

Correct it to the actual reference

Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/Documentation/RCU/RTFP.txt b/Documentation/RCU/RTFP.txt
index 7c1dfb1..7f40c72 100644
--- a/Documentation/RCU/RTFP.txt
+++ b/Documentation/RCU/RTFP.txt
@@ -186,7 +186,7 @@
 
 @article{Kung80
 ,author="H. T. Kung and Q. Lehman"
-,title="Concurrent Maintenance of Binary Search Trees"
+,title="Concurrent Manipulation of Binary Search Trees"
 ,Year="1980"
 ,Month="September"
 ,journal="ACM Transactions on Database Systems"