Convert vbutil_what_keys to use /bin/sh

This just involves deleting the "set -o pipefail" line. With
bash, that meant that any program failure in a pipe would be
fatal. Without it, only the last program matters. This usually
means that the last command simply gets no input, in which case
the program just appears to do nothing instead of complaining
about whatever the problem was.

Since vbutil_what_keys is generally only used to help debug a
failure to boot, that's not a major problem.

BUG=chromium:419773
BRANCH=ToT
TEST=manual

Tried on a Pit, it works:

localhost ~ # /tmp/vbutil_what_keys /dev/mmcblk0
-e
IMAGE: /dev/mmcblk0
  part 2 kernel:   d6170aa480136f1f29cf339a5ab1b960585fa444  (!DEV DEV !REC)  developer keys
  part 4 kernel:   d6170aa480136f1f29cf339a5ab1b960585fa444  (!DEV DEV !REC)  developer keys

localhost ~ # flashrom -r /tmp/bios.bin
flashrom v0.9.4  : 904e8a5 : Sep 22 2014 20:47:40 UTC on Linux 3.8.11 (armv7l), built with libpci 3.1.10, GCC 4.8.x-google 20140307 (prerelease), little endian
Reading flash... SUCCESS
localhost ~ # /tmp/vbutil_what_keys /tmp/bios.bin
-e
BIOS: /tmp/bios.bin
  hwid:          PIT D3A-D4Q-A3L
  root key:      a026a7a4a0bf0fa32d6b7aa90a80d5ef01a3b799  Daisy MP-v3, Peach-Pi MP, Peach-Pit MP-v2, Snow MP
  recovery key:  6d9a2ca8b3080a97e1e5a4efbc5386ead77c3c7f  Peach-Pit MP-v2

localhost ~ #

Change-Id: I171da3bf688032f469d7a5cdb42278d8028b7e0d
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/221176
Reviewed-by: Mike Frysinger <vapier@chromium.org>

utility/vbutil_what_keys

@@ -1,5 +1,5 @@
-#!/bin/bash -u
+#!/bin/sh -u
-# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+# Copyright (c) 2014 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.
 
@@ -33,8 +33,6 @@ fi
 # {FA42644C-CF3A-4692-A9D3-1A667CB232E9}    ZGB H2C
 
 
-set -o pipefail
-
 # args?
 unpack_it=
 verbose=