Remove obsolete channel_change and mkcrosusb commands.

mkcrosusb

Index: mkcrosusb
diff --git a/mkcrosusb b/mkcrosusb
deleted file mode 100755
index f0b23a9ea754c71d18fac9f7cefc673f9635157d..0000000000000000000000000000000000000000
--- a/mkcrosusb
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/bin/bash
-#
-PROG=$(basename $0)
-# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-#
-# Script to make ChromeOS image to USB.
-###############################################################################
-# Syntax:
-# bash mkcros.sh $1 where $1 is -beta or -rcbeta or -dev or -rcdev.
-# e.g. to download latest released beta-channel:
-# bash mkcrosusb.sh --beta
-###############################################################################
-#
-# simplify making an image
-#
-
-# Help info
-echo
-echo "Please visit chrome://imageburner to create new recovery devices!"
-echo
-exit 1