kselftest/arm64: fix array_size.cocci warning

Use ARRAY_SIZE to fix the following coccicheck warnings:
tools/testing/selftests/arm64/mte/check_buffer_fill.c:341:20-21:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_buffer_fill.c:35:20-21:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_buffer_fill.c:168:20-21:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_buffer_fill.c:72:20-21:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_buffer_fill.c:369:25-26:
WARNING: Use ARRAY_SIZE

Signed-off-by: Kang Minchul <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

tools/testing/selftests/arm64/mte/check_buffer_fill.c

···
 	bool err;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 
 	for (i = 0; i < item; i++) {
 		ptr = (char *)mte_allocate_memory(sizes[i], mem_type, 0, true);
···
 	char *und_ptr = NULL;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 	for (i = 0; i < item; i++) {
 		ptr = (char *)mte_allocate_memory_tag_range(sizes[i], mem_type, 0,
 							    underflow_range, 0);
···
 	char *over_ptr = NULL;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 	for (i = 0; i < item; i++) {
 		ptr = (char *)mte_allocate_memory_tag_range(sizes[i], mem_type, 0,
 							    0, overflow_range);
···
 	int i, item, result = KSFT_PASS;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 	cur_mte_cxt.fault_valid = false;
 	for (i = 0; i < item; i++) {
 		result = check_buffer_by_block_iterate(mem_type, mode, sizes[i]);
···
 {
 	char *ptr;
 	int run, fd;
-	int total = sizeof(sizes)/sizeof(int);
+	int total = ARRAY_SIZE(sizes);
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
 	for (run = 0; run < total; run++) {
···
 {
 	int err;
 	size_t page_size = getpagesize();
-	int item = sizeof(sizes)/sizeof(int);
+	int item = ARRAY_SIZE(sizes);
 
 	sizes[item - 3] = page_size - 1;
 	sizes[item - 2] = page_size;