Do not pass dm-verity options to build_kernel_image.
Do not pass dm-verity options to build_kernel_image.

* Since dm-verity arguments are now read from the install image upon
  recovery, we need not use them in build_kernel_image.

* Also, don't expect or remove /tmp/rootfs.hash, which will not be
  generated by build_kernel_image.

* Cleanup of dead code following the elimination of use of root_dev.

* Updated ASCII art for success/failure condition.

* See corresponding changes to initramfs script (extract verity args
  from install kernel) and chromeos-initramfs ebuild (pull
  dump_kernel_config).

BUG=chromium-os:22530
TEST=Built and successfully installed recovery image on CR-48

Change-Id: I3536c88537bbce277f79f17b676231b67337a0d1
Reviewed-on: https://gerrit.chromium.org/gerrit/12646
Reviewed-by: Gilad Arnold <a0dab390cfdc583218cee97b60c5c4eb1be355d2@chromium.org>
Tested-by: Gilad Arnold <a0dab390cfdc583218cee97b60c5c4eb1be355d2@chromium.org>
Commit-Ready: Gilad Arnold <a0dab390cfdc583218cee97b60c5c4eb1be355d2@chromium.org>

zhang0137/scripts,mjg59/scripts,smilart/scripts,trnubo/scripts,sigma/coreos-scripts,mjg59/scripts,BugRoger/scripts,marineam/coreos-scripts,andrejro/coreos--scripts,endocode/scripts,coreos/scripts,sigma/coreos-scripts,sigma/coreos-scripts,fivethreeo/scripts,zhang0137/scripts,nicescale/scripts,vmware/coreos-scripts,endocode/scripts,mischief/scripts,mischief/scripts,crawford/scripts,zhang0137/scripts,trnubo/scripts,nicescale/scripts,marineam/coreos-scripts,fivethreeo/scripts,vmware/coreos-scripts,andrejro/coreos--scripts,bcwaldon/coreos-scripts,gtank/scripts,bcwaldon/coreos-scripts,andrejro/coreos--scripts,coreos/scripts,mjg59/scripts,smilart/scripts,mischief/scripts,gtank/scripts,glevand/coreos--scripts,nicescale/scripts,crawford/scripts,crawford/scripts,gtank/scripts,glevand/coreos--scripts,BugRoger/scripts,vmware/coreos-scripts,marineam/coreos-scripts,fivethreeo/scripts,BugRoger/scripts,smilart/scripts,bcwaldon/coreos-scripts,endocode/scripts,trnubo/scripts