arrayRCU.rst has been removed since commit ef2555cf ("doc: Remove
arrayRCU.rst") but is still referenced by whatisRCU.rst. Update it to
reflect the current state of the documentation.
Signed-off-by: Zenghui Yu <zenghui.yu@linux.dev>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>