perf evlist: Introduce evsel list accessors

To replace the longer list_entry constructs for things that are widely
used:

	perf_evlist__{first,last}(evlist)
	perf_evsel__next(evsel)

Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@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 <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ng7azq26wg1jd801qqpcozwp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5a097be..0513aaa 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -509,7 +509,7 @@
 				prompt_integer(&counter, "Enter details event counter");
 
 				if (counter >= top->evlist->nr_entries) {
-					top->sym_evsel = list_entry(top->evlist->entries.next, struct perf_evsel, node);
+					top->sym_evsel = perf_evlist__first(top->evlist);
 					fprintf(stderr, "Sorry, no such event, using %s.\n", perf_evsel__name(top->sym_evsel));
 					sleep(1);
 					break;
@@ -518,7 +518,7 @@
 					if (top->sym_evsel->idx == counter)
 						break;
 			} else
-				top->sym_evsel = list_entry(top->evlist->entries.next, struct perf_evsel, node);
+				top->sym_evsel = perf_evlist__first(top->evlist);
 			break;
 		case 'f':
 			prompt_integer(&top->count_filter, "Enter display event count filter");
@@ -1326,7 +1326,7 @@
 			pos->attr.sample_period = top.default_interval;
 	}
 
-	top.sym_evsel = list_entry(top.evlist->entries.next, struct perf_evsel, node);
+	top.sym_evsel = perf_evlist__first(top.evlist);
 
 	symbol_conf.priv_size = sizeof(struct annotation);