perf evlist: Pass the event_group info via perf_attr_details

So that we avoid dragging symbol.o into the python binding.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-izjubje7ltd1srji5wb0ygwi@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index a547015..9c82f98f 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1391,7 +1391,7 @@
 	bool first = true;
 	int printed = 0;
 
-	if (symbol_conf.event_group) {
+	if (details->event_group) {
 		struct perf_evsel *pos;
 
 		if (!perf_evsel__is_group_leader(evsel))