perf tools: Use perf_evlist__{first,last}, perf_evsel__next

In a few remaining places where the equivalent open coded variant was
still being used.

Cc: Adrian Hunter <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/parse-events.c

···
 
 static int test__checkevent_pmu_events(struct perf_evlist *evlist)
 {
-	struct perf_evsel *evsel;
+	struct perf_evsel *evsel = perf_evlist__first(evlist);
 
-	evsel = list_entry(evlist->entries.next, struct perf_evsel, node);
 	TEST_ASSERT_VAL("wrong number of entries", 1 == evlist->nr_entries);
 	TEST_ASSERT_VAL("wrong type", PERF_TYPE_RAW == evsel->attr.type);
 	TEST_ASSERT_VAL("wrong exclude_user",

tools/perf/ui/browsers/hists.c

···
 			switch (key) {
 			case K_TAB:
 				if (pos->node.next == &evlist->entries)
-					pos = list_entry(evlist->entries.next, struct perf_evsel, node);
+					pos = perf_evlist__first(evlist);
 				else
-					pos = list_entry(pos->node.next, struct perf_evsel, node);
+					pos = perf_evsel__next(pos);
 				goto browse_hists;
 			case K_UNTAB:
 				if (pos->node.prev == &evlist->entries)
-					pos = list_entry(evlist->entries.prev, struct perf_evsel, node);
+					pos = perf_evlist__last(evlist);
 				else
 					pos = list_entry(pos->node.prev, struct perf_evsel, node);
 				goto browse_hists;
···
 
 single_entry:
 	if (nr_entries == 1) {
-		struct perf_evsel *first = list_entry(evlist->entries.next,
-						      struct perf_evsel, node);
+		struct perf_evsel *first = perf_evlist__first(evlist);
 		const char *ev_name = perf_evsel__name(first);
 
 		return perf_evsel__hists_browse(first, nr_entries, help,