[PATCH] selftests: harness: Mark test fixture objects __maybe_unused

[David Matlack <dmatlack@google.com>]

Mark test fixture objects __maybe_unused since they will not be used
when there are fixture variants (the variants will be used instead).

This fixes the VFIO selftest build with clang and -Werror:

vfio_dma_mapping_mmio_test.c:106:1: error: variable '_vfio_dma_mapping_mmio_test_map_full_bar_object' set but not used [-Werror,-Wunused-but-set-global]
  106 | TEST_F(vfio_dma_mapping_mmio_test, map_full_bar)
      | ^
./../kselftest_harness.h:398:2: note: expanded from macro 'TEST_F'
  398 |         __TEST_F_IMPL(fixture_name, test_name, -1, TEST_TIMEOUT_DEFAULT)
      |         ^
./../kselftest_harness.h:470:33: note: expanded from macro '__TEST_F_IMPL'
  470 |         static struct __test_metadata *_##fixture_name##_##test_name##_object; \
      |

Fixes: ff556bd98348 ("vfio: selftests: Add -Wall and -Werror to the Makefile")
Reported-by: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/kselftest_harness.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index 261e4df94d9d..29a19bc87084 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -467,7 +467,7 @@ static inline void __kselftest_memset_safe(void *s, int c, size_t n)
 				!__atomic_test_and_set(_metadata->no_teardown, __ATOMIC_RELAXED)) \
 			fixture_name##_teardown(_metadata, self, variant); \
 	} \
-	static struct __test_metadata *_##fixture_name##_##test_name##_object; \
+	static struct __test_metadata *_##fixture_name##_##test_name##_object __maybe_unused; \
 	static void __attribute__((constructor(KSELFTEST_PRIO_TEST))) \
 			_register_##fixture_name##_##test_name(void) \
 	{ \

base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
-- 
2.55.0.rc0.799.gd6f94ed593-goog