In evsel__tp_format(), when trace_event__tp_format*() returns an error,
IS_ERR() checks the local variable 'tp_format', but PTR_ERR() incorrectly
uses 'evsel->tp_format' which hasn't been assigned yet.

Fix this by using PTR_ERR(tp_format) to extract the error code from the
correct variable.

Fixes: 6c8310e8380d ("perf evsel: Allow evsel__newtp without libtraceevent")
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
---
 tools/perf/util/evsel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 2ee87fd84d3e..0cefeba41236 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -647,7 +647,7 @@ struct tep_event *evsel__tp_format(struct evsel *evsel)
 		tp_format = trace_event__tp_format(evsel->tp_sys, evsel->tp_name);
 
 	if (IS_ERR(tp_format)) {
-		int err = -PTR_ERR(evsel->tp_format);
+		int err = -PTR_ERR(tp_format);
 
 		errno = err;
 		pr_err("Error getting tracepoint format '%s': %m\n",
-- 
2.25.1