tests/coding: cosmetic: use ARRAY_SIZE() macro from utils.h

Change-Id: Ie6278d84d405f073669e607f978ca5b187bcf78e
diff --git a/tests/coding/coding_test.c b/tests/coding/coding_test.c
index 087a593..2ae95f8 100644
--- a/tests/coding/coding_test.c
+++ b/tests/coding/coding_test.c
@@ -384,8 +384,8 @@
 {
 	int i, len_l2, len_mb;
 
-	len_l2 = sizeof(test_l2) / sizeof(test_l2[0]);
-	len_mb = sizeof(test_macblock) / sizeof(test_macblock[0]);
+	len_l2 = ARRAY_SIZE(test_l2);
+	len_mb = ARRAY_SIZE(test_macblock);
 
 	for (i = 0; i < len_l2; i++)
 		test_xcch(test_l2[i]);