mm/damon/tests/dbgfs-kunit: fix the header double inclusion guarding ifdef comment

Closing part of double inclusion guarding macro for dbgfs-kunit.h was
copy-pasted from somewhere (maybe before the initial mainline merge of
DAMON), and not properly updated.  Fix it.

Link: https://lkml.kernel.org/r/20241028233058.283381-7-sj@kernel.org
Fixes: 17ccae8bb5 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Andrew Paniakin <apanyaki@amazon.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/tests/dbgfs-kunit.h

@@ -168,6 +168,6 @@ static struct kunit_suite damon_test_suite = {
 };
 kunit_test_suite(damon_test_suite);
 
-#endif /* _DAMON_TEST_H */
+#endif /* _DAMON_DBGFS_TEST_H */
 
 #endif	/* CONFIG_DAMON_KUNIT_TEST */