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.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/hists_cumulate.c

@@ -706,6 +706,7 @@ int test__hists_cumulate(int subtest __maybe_unused)
 	err = parse_events(evlist, "cpu-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	machines__init(&machines);
 

tools/perf/tests/hists_filter.c

@@ -120,6 +120,7 @@ int test__hists_filter(int subtest __maybe_unused)
 	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)

tools/perf/tests/hists_link.c

@@ -293,6 +293,7 @@ int test__hists_link(int subtest __maybe_unused)
 	if (err)
 		goto out;
 
+	err = TEST_FAIL;
 	/* default sort order (comm,dso,sym) will be used */
 	if (setup_sorting(NULL) < 0)
 		goto out;

tools/perf/tests/hists_output.c

@@ -597,6 +597,7 @@ int test__hists_output(int subtest __maybe_unused)
 	err = parse_events(evlist, "cpu-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	machines__init(&machines);