kselftest/arm64: fix array_size.cocci warning

Fix following coccicheck warning:

tools/testing/selftests/arm64/mte/check_mmap_options.c:64:24-25:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_mmap_options.c:66:20-21:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_mmap_options.c:135:25-26:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_mmap_options.c:96:25-26:
WARNING: Use ARRAY_SIZE
tools/testing/selftests/arm64/mte/check_mmap_options.c:190:24-25:
WARNING: Use ARRAY_SIZE

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

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

···
 {
 	char *ptr, *map_ptr;
 	int run, result, map_size;
-	int item = sizeof(sizes)/sizeof(int);
+	int item = ARRAY_SIZE(sizes);
 
-	item = sizeof(sizes)/sizeof(int);
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
 	for (run = 0; run < item; run++) {
 		map_size = sizes[run] + OVERFLOW + UNDERFLOW;
···
 {
 	char *ptr, *map_ptr;
 	int run, fd, map_size;
-	int total = sizeof(sizes)/sizeof(int);
+	int total = ARRAY_SIZE(sizes);
 	int result = KSFT_PASS;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
···
 {
 	char *ptr, *map_ptr;
 	int run, prot_flag, result, fd, map_size;
-	int total = sizeof(sizes)/sizeof(int);
+	int total = ARRAY_SIZE(sizes);
 
 	prot_flag = PROT_READ | PROT_WRITE;
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
···
 int main(int argc, char *argv[])
 {
 	int err;
-	int item = sizeof(sizes)/sizeof(int);
+	int item = ARRAY_SIZE(sizes);
 
 	err = mte_default_setup();
 	if (err)