perf sched: Usage leftover from trace -> script rename

The 'perf sched' command usage still showing 'trace' command instead of
the 'script' command.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110809124651.GD2056@jolsa.brq.redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-sched.c

@@ -1777,7 +1777,7 @@ static void __cmd_replay(void)
 
 
 static const char * const sched_usage[] = {
-	"perf sched [<options>] {record|latency|map|replay|trace}",
+	"perf sched [<options>] {record|latency|map|replay|script}",
 	NULL
 };