perf test: Reset err after using it hold errcode in hist testcases

All hists test cases forget to reset err after using it to hold an
error code. If error occure in setup_fake_machine() it incorrectly
return TEST_OK.

This patch fixes it.

Suggested-and-Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452520124-2073-13-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/hists_cumulate.c b/tools/perf/tests/hists_cumulate.c
index e360892..5e6a86e 100644
--- a/tools/perf/tests/hists_cumulate.c
+++ b/tools/perf/tests/hists_cumulate.c
@@ -706,6 +706,7 @@
 	err = parse_events(evlist, "cpu-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	machines__init(&machines);
 
diff --git a/tools/perf/tests/hists_filter.c b/tools/perf/tests/hists_filter.c
index 2a784be..351a424 100644
--- a/tools/perf/tests/hists_filter.c
+++ b/tools/perf/tests/hists_filter.c
@@ -120,6 +120,7 @@
 	err = parse_events(evlist, "task-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	/* default sort order (comm,dso,sym) will be used */
 	if (setup_sorting(NULL) < 0)
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index c764d69..64b257d 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -293,6 +293,7 @@
 	if (err)
 		goto out;
 
+	err = TEST_FAIL;
 	/* default sort order (comm,dso,sym) will be used */
 	if (setup_sorting(NULL) < 0)
 		goto out;
diff --git a/tools/perf/tests/hists_output.c b/tools/perf/tests/hists_output.c
index ebe6cd4..b231265 100644
--- a/tools/perf/tests/hists_output.c
+++ b/tools/perf/tests/hists_output.c
@@ -597,6 +597,7 @@
 	err = parse_events(evlist, "cpu-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	machines__init(&machines);