perf tools: Remove stale git headlines from top comment

These files are part of PERF not GIT although they're come from there :)

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323784323-2150-1-git-send-email-namhyung@gmail.comSigned-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/config.c

 /*
- * GIT - The information manager from hell
+ * config.c
+ *
+ * Helper functions for parsing config items.
+ * Originally copied from GIT source.
  *
  * Copyright (C) Linus Torvalds, 2005
  * Copyright (C) Johannes Schindelin, 2005

tools/perf/util/usage.c

 /*
- * GIT - The information manager from hell
+ * usage.c
+ *
+ * Various reporting routines.
+ * Originally copied from GIT source.
  *
  * Copyright (C) Linus Torvalds, 2005
  */