perf session: Change perf_session__has_traces to actually check for tracepoints

Any event can have RAW data attribute set. The intent of the function is
to determine if the session has tracepoints, so check for the type of
each event explicitly.
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375930261-77273-17-git-send-email-dsahern@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -1401,12 +1401,15 @@ int perf_session__process_events(struct perf_session *self,
 
 bool perf_session__has_traces(struct perf_session *session, const char *msg)
 {
-	if (!(perf_evlist__sample_type(session->evlist) & PERF_SAMPLE_RAW)) {
-		pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
-		return false;
-	}
+	struct perf_evsel *evsel;
 
+	list_for_each_entry(evsel, &session->evlist->entries, node) {
+		if (evsel->attr.type == PERF_TYPE_TRACEPOINT)
 			return true;
+	}
+
+	pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
+	return false;
 }
 
 int maps__set_kallsyms_ref_reloc_sym(struct map **maps,