Update documentation to note the passage of INIT_RCU_HEAD()

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

Documentation/DocBook/kernel-locking.tmpl

@@ -1725,14 +1725,6 @@ the amount of locking which needs to be done.
          if (++cache_num > MAX_CACHE_SIZE) {
                  struct object *i, *outcast = NULL;
                  list_for_each_entry(i, &cache, list) {
-@@ -85,6 +94,7 @@
-         obj->popularity = 0;
-         atomic_set(&obj->refcnt, 1); /* The cache holds a reference */
-         spin_lock_init(&obj->lock);
-+        INIT_RCU_HEAD(&obj->rcu);
-
-         spin_lock_irqsave(&cache_lock, flags);
-         __cache_add(obj);
 @@ -104,12 +114,11 @@
  struct object *cache_find(int id)
  {