perf evlist: Simplify set_maps() logic

Don't need to check for NULL when "putting" evlist->maps and
evlist->threads because the "put" functions already do that.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Link: http://lkml.kernel.org/r/1441699142-18905-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 95e07ea..9cb9296 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1156,14 +1156,10 @@
 			  struct cpu_map *cpus,
 			  struct thread_map *threads)
 {
-	if (evlist->cpus)
-		cpu_map__put(evlist->cpus);
-
+	cpu_map__put(evlist->cpus);
 	evlist->cpus = cpus;
 
-	if (evlist->threads)
-		thread_map__put(evlist->threads);
-
+	thread_map__put(evlist->threads);
 	evlist->threads = threads;
 
 	return perf_evlist__propagate_maps(evlist, false);