perf evlist: Introduce evlist__for_each() & friends

For the common evsel list traversal, so that it becomes more compact.

Use the opportunity to start ditching the 'perf_' from 'perf_evlist__',
as discussed, as the whole conversion touches a lot of places, lets do
it piecemeal when we have the chance due to other work, like in this
case.

Cc: Adrian Hunter <adrian.hunter@intel.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@kernel.org>
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-qnkx7dzm2h6m6uptkfk03ni6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 8ffe29c..7acc03e 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1384,7 +1384,7 @@
 {
 	struct perf_evsel *evsel;
 
-	list_for_each_entry(evsel, &session->evlist->entries, node) {
+	evlist__for_each(session->evlist, evsel) {
 		if (evsel->attr.type == PERF_TYPE_TRACEPOINT)
 			return true;
 	}
@@ -1442,7 +1442,7 @@
 
 	ret += events_stats__fprintf(&session->stats, fp);
 
-	list_for_each_entry(pos, &session->evlist->entries, node) {
+	evlist__for_each(session->evlist, pos) {
 		ret += fprintf(fp, "%s stats:\n", perf_evsel__name(pos));
 		ret += events_stats__fprintf(&pos->hists.stats, fp);
 	}
@@ -1464,7 +1464,7 @@
 {
 	struct perf_evsel *pos;
 
-	list_for_each_entry(pos, &session->evlist->entries, node) {
+	evlist__for_each(session->evlist, pos) {
 		if (pos->attr.type == type)
 			return pos;
 	}