perf evlist: Fix id pos in perf_evlist__open()

Ensure the id_pos is correct when perf_evlist__open() is used.

This fixes a problem introduced in 7556257 that broke 'perf kvm stat
live' in that this tool wasn't updated to use the sample_type bits
setting helpers.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: David Ahern <dsahern@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
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 <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1378496412-2424-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evlist.c

@@ -64,6 +64,16 @@ void perf_evlist__set_id_pos(struct perf_evlist *evlist)
 	evlist->is_pos = first->is_pos;
 }
 
+static void perf_evlist__update_id_pos(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel;
+
+	list_for_each_entry(evsel, &evlist->entries, node)
+		perf_evsel__calc_id_pos(evsel);
+
+	perf_evlist__set_id_pos(evlist);
+}
+
 static void perf_evlist__purge(struct perf_evlist *evlist)
 {
 	struct perf_evsel *pos, *n;
@@ -920,6 +930,8 @@ int perf_evlist__open(struct perf_evlist *evlist)
 	struct perf_evsel *evsel;
 	int err;
 
+	perf_evlist__update_id_pos(evlist);
+
 	list_for_each_entry(evsel, &evlist->entries, node) {
 		err = perf_evsel__open(evsel, evlist->cpus, evlist->threads);
 		if (err < 0)