rcutorture: Use ARRAY_SIZE macro when appropriate

Use ARRAY_SIZE macro already defined in kernel.h

Signed-off-by: Ahmed S. Darwish <[e-mail]>
Cc: "Paul E. McKenney" <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

kernel/rcutorture.c

···
 	/* Set up the freelist. */
 
 	INIT_LIST_HEAD(&rcu_torture_freelist);
-	for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) {
+	for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
 		rcu_tortures[i].rtort_mbtest = 0;
 		list_add_tail(&rcu_tortures[i].rtort_free,
 			      &rcu_torture_freelist);