Remove cros_workon trampoline.

This is replaced by the Pythonic command of the same name from chromite.

BUG=brillo:817
TEST=sudo emerge -C chromeos-base/cros-devutils; sudo emerge
chromeos-base/cros-devutils succeeds.

CQ-DEPEND=CL:266752

Change-Id: Ib60dbc23f93e348b600dd2e21175534b3a30efdf
Reviewed-on: https://chromium-review.googlesource.com/266773
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Bertrand Simonnet <bsimonnet@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>
diff --git a/host/cros_workon b/host/cros_workon
deleted file mode 100755
index 376be76..0000000
--- a/host/cros_workon
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/bash
-
-# Copyright (c) 2012 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.
-
-. /usr/lib/crosutils/common.sh || exit 1
-
-"${SCRIPTS_DIR}/cros_workon" "$@"