toctree index title ("RCU concepts") is rather a misnomer: RCU concepts
is already described in rcu.rst, whereas the toctree suggests that
the docs themes about handbook on RCU subsystem instead.

Edit the title to reflect the fact.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 Documentation/RCU/index.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/RCU/index.rst b/Documentation/RCU/index.rst
index e1be5b3c2c6773..ef26c78507d369 100644
--- a/Documentation/RCU/index.rst
+++ b/Documentation/RCU/index.rst
@@ -1,9 +1,9 @@
 .. SPDX-License-Identifier: GPL-2.0
 
-.. _rcu_concepts:
+.. _rcu_handbook:
 
 ============
-RCU concepts
+RCU Handbook
 ============
 
 .. toctree::
-- 
An old man doll... just what I always wanted! - Clara