Follow-up on UEFI/Grub2 job
Follow-up on UEFI/Grub2 job

Makes some minor requested changes to the
devstack script that were added/changed
in order to support UEFI/GRUB2 booting
in CI.

Change-Id: I6a582cc2970911c9c827309d034e4553a09b66df

openstack/ironic,openstack/ironic