kvfree_rcu: Use kfree_rcu_monitor() instead of open-coded variant

Replace an open-coded version of the kfree_rcu_monitor() function body
with a call to that function.
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

kernel/rcu/tree.c

@@ -3697,7 +3697,6 @@ static unsigned long
 kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
 	int cpu, freed = 0;
-	unsigned long flags;
 
 	for_each_possible_cpu(cpu) {
 		int count;
@@ -3705,12 +3704,7 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 
 		count = krcp->count;
 		count += drain_page_cache(krcp);
-
-		raw_spin_lock_irqsave(&krcp->lock, flags);
-		if (krcp->monitor_todo)
-			kfree_rcu_drain_unlock(krcp, flags);
-		else
-			raw_spin_unlock_irqrestore(&krcp->lock, flags);
+		kfree_rcu_monitor(&krcp->monitor_work.work);
 
 		sc->nr_to_scan -= count;
 		freed += count;