[PATCH 7/8] perf stat: Fix error return code in cmd_stat

[Shang XiaoJing <shangxiaojing@huawei.com>]

Reset the error return value in cmd_stat as -EINVAL after assigned, and
use the specific error code of evlist__expand_cgroup, for correct error
code.

BTW, change the default error code of evlist__expand_cgroup to ensure it
can return specific value instead of -1.

Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
---
 tools/perf/builtin-stat.c | 9 +++++++--
 tools/perf/util/cgroup.c  | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 54cd29d07ca8..559ffa107218 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -2427,6 +2427,7 @@ int cmd_stat(int argc, const char **argv)
 			iostat_list(evsel_list, &stat_config);
 		if (iostat_mode == IOSTAT_RUN && !target__has_cpu(&target))
 			target.system_wide = true;
+		status = -EINVAL;
 	}
 
 	if (add_default_attributes())
@@ -2440,12 +2441,16 @@ int cmd_stat(int argc, const char **argv)
 			goto out;
 		}
 
-		if (evlist__expand_cgroup(evsel_list, stat_config.cgroup_list,
-					  &stat_config.metric_events, true) < 0) {
+		status = evlist__expand_cgroup(evsel_list,
+					       stat_config.cgroup_list,
+					       &stat_config.metric_events,
+					       true);
+		if (status < 0) {
 			parse_options_usage(stat_usage, stat_options,
 					    "for-each-cgroup", 0);
 			goto out;
 		}
+		status = -EINVAL;
 	}
 
 	if ((stat_config.aggr_mode == AGGR_THREAD) && (target.system_wide))
diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
index e99b41f9be45..e3c6fc54dde5 100644
--- a/tools/perf/util/cgroup.c
+++ b/tools/perf/util/cgroup.c
@@ -400,7 +400,7 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str,
 	struct rblist orig_metric_events;
 	struct cgroup *cgrp = NULL;
 	struct cgroup_name *cn;
-	int ret = -1;
+	int ret = -EINVAL;
 	int prefix_len;
 
 	if (evlist->core.nr_entries == 0) {
-- 
2.17.1