selftests: vDSO: vdso_test_abi: Use ksft_finished()

The existing logic is just an open-coded ksft_finished().
Replace it with the real thing.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250812-vdso-tests-fixes-v2-3-90f499dd35f8@linutronix.de

Author: t-8ch

tools/testing/selftests/vDSO/vdso_test_abi.c

@@ -231,6 +231,5 @@ int main(int argc, char **argv)
 
 	vdso_test_time();
 
-	ksft_print_cnts();
-	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+	ksft_finished();
 }