[Merge] ~mwhudson/livecd-rootfs/+git/livecd-rootfs:fix-disk-image-binary-s390x-harder into livecd-rootfs:ubuntu/master

[Michael Hudson-Doyle]

Yes I guess it would be good to implement this on s390x... but for now I just want it to migrate.
-- 
https://code.launchpad.net/~mwhudson/livecd-rootfs/+git/livecd-rootfs/+merge/448024
Your team Ubuntu Core Development Team is subscribed to branch livecd-rootfs:ubuntu/master.