install: fix shell redirections

chromeos-postinst

 #!/bin/sh
 
 # Copyright (c) 2009 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.
 
 # This script is called after an AutoUpdate or USB install. The first argument
 # is the partition where the new rootfs is installed or empty. If non-empty
 # the rootfs should be updated w/ the new bootloader config. If empty, the
 # rootfs is mounted-read only and should not be updated.
@@ skipping 54 matching lines @@
 LEGACY_PART_NUM=12
 
 if [ "${FLAGS_postcommit}" -eq "${FLAGS_FALSE}" ]; then
   # Pre-commit. Returning an error here will prevent ever booting into the
   # installed system.
 
   echo "Postinst running"
 
   # If this FS was mounted read-write, we can't do deltas from it. Mark the
   # FS as such
-  touch "${INSTALL_ROOT}/.nodelta" || true 2>&1 > /dev/null
+  (touch "${INSTALL_ROOT}/.nodelta" || true) > /dev/null 2>&1
 
   # TODO(zelidrag): http://crosbug/6367 - Remove this before the product is
   # released. For now, this should recover users that reimaged their machine.
   if [ -f /home/chronos/.oobe_completed ]; then
     CONSENT_FILE="/home/chronos/Consent To Send Stats"
     if [ ! -f "$CONSENT_FILE" ]; then
       "${INSTALL_ROOT}/usr/bin/uuidgen" > "$CONSENT_FILE"
     fi
   fi
 
@@ skipping 256 matching lines @@
     echo "marking part $LEGACY_PART_NUM bootable (new)"
     "${INSTALL_ROOT}"/usr/bin/cgpt boot -i $LEGACY_PART_NUM ${ROOT_DEV} 2>&1
   else
     # The old gpt tool requires a -b arg to specify the PMBR bootcode. We don't
     # want to change the code, so we have to extract it, then put it back.
     dd if=${ROOT_DEV} bs=512 count=1 of=/tmp/oldpmbr.bin
     echo "marking part $LEGACY_PART_NUM bootable (old)"
     gpt -S boot -i $LEGACY_PART_NUM -b /tmp/oldpmbr.bin ${ROOT_DEV} 2>&1
   fi
 fi