perf stat: Fix tool option consistency: rename -S/--scale to -c/--scale

We want to use a coherent flag for -S/--stat across all tools,
so free up -S in perf stat.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 0d74346..484080d 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -40,7 +40,7 @@
 -a::
         system-wide collection
 
--S::
+-c::
         scale counter values
 
 EXAMPLES