The task_cls_classid() function applies rcu_dereference() to integers,
which does not work with the shiny new sparse-based checking in
rcu_dereference().  This commit therefore moves to the new RCU API
rcu_dereference_index_check().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
                return 0;
 
        rcu_read_lock();
-       id = rcu_dereference(net_cls_subsys_id);
+       id = rcu_dereference_index_check(net_cls_subsys_id,
+                                        rcu_read_lock_held());
        if (id >= 0)
                classid = container_of(task_subsys_state(p, id),
                                       struct cgroup_cls_state, css)->classid;