rcu: Remove remaining read-modify-write ACCESS_ONCE() calls

Change the remaining uses of ACCESS_ONCE() so that each ACCESS_ONCE() either does a load or a store, but not both.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index a7997e2..218fae3 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -897,7 +897,8 @@
 
 	/* Clean up and exit. */
 	smp_mb(); /* ensure expedited GP seen before counter increment. */
-	ACCESS_ONCE(sync_rcu_preempt_exp_count)++;
+	ACCESS_ONCE(sync_rcu_preempt_exp_count) =
+					sync_rcu_preempt_exp_count + 1;
 unlock_mb_ret:
 	mutex_unlock(&sync_rcu_preempt_exp_mutex);
 mb_ret:
@@ -2428,8 +2429,9 @@
 			list = next;
 		}
 		trace_rcu_batch_end(rdp->rsp->name, c, !!list, 0, 0, 1);
-		ACCESS_ONCE(rdp->nocb_p_count) -= c;
-		ACCESS_ONCE(rdp->nocb_p_count_lazy) -= cl;
+		ACCESS_ONCE(rdp->nocb_p_count) = rdp->nocb_p_count - c;
+		ACCESS_ONCE(rdp->nocb_p_count_lazy) =
+						rdp->nocb_p_count_lazy - cl;
 		rdp->n_nocbs_invoked += c;
 	}
 	return 0;