perf bench sched-messaging: Plug memleak

Explicitly free the thread array ('pth_tab').

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1402942467-10671-5-git-send-email-davidlohr@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bench/sched-messaging.c

@@ -332,5 +332,7 @@ int bench_sched_messaging(int argc, const char **argv,
 		break;
 	}
 
+	free(pth_tab);
+
 	return 0;
 }