perf test: Fix build failure

The commit 6a6cd11d ("perf test: Add test for the sched tracepoint
format fields") added following build error:

    CC builtin-test.o
  builtin-test.c: In function ‘perf_evsel__test_field’:
  builtin-test.c:1216:6: error: variable ‘ret’ set but not used [-Werror=unused-but-set-variable]
  builtin-test.c: In function ‘perf_evsel__tp_sched_test’:
  builtin-test.c:1242:6: error: variable ‘ret’ set but not used [-Werror=unused-but-set-variable]
  cc1: all warnings being treated as errors
  make: *** [builtin-test.o] Error 1
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1348539628-3821-1-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-test.c

@@ -1233,7 +1233,7 @@ static int perf_evsel__test_field(struct perf_evsel *evsel, const char *name,
 		ret = -1;
 	}
 
-	return 0;
+	return ret;
 }
 
 static int perf_evsel__tp_sched_test(void)
@@ -1286,7 +1286,7 @@ static int perf_evsel__tp_sched_test(void)
 	if (perf_evsel__test_field(evsel, "target_cpu", 4, true))
 		ret = -1;
 
-	return 0;
+	return ret;
 }
 
 static struct test {