kselftest/arm64: Fix check_mmap_options test

The check_mmap_options test reports the error below because the test
plan is not declared correctly:

# Planned tests != run tests (0 != 22)

Fix the test adding the correct test plan declaration.

Fixes: 53ec81d23213 ("kselftest/arm64: Verify all different mmap MTE options")
Signed-off-by: Vincenzo Frascino <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Gabor Kertesz <[e-mail]>
Cc: Amit Daniel Kachhap <[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

···
 	mte_register_signal(SIGBUS, mte_default_handler);
 	mte_register_signal(SIGSEGV, mte_default_handler);
 
+	/* Set test plan */
+	ksft_set_plan(22);
+
 	mte_enable_pstate_tco();
+
 	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_OFF),
 	"Check anonymous memory with private mapping, sync error mode, mmap memory and tag check off\n");
 	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_OFF),