[Merge] ~gjolly/livecd-rootfs:ubuntu-cpc/device_busy into livecd-rootfs:ubuntu/master

[Michael Hudson-Doyle]

I don't mean to be especially contrary but do you have evidence that if waiting 30s isn't enough, that waiting longer will help? I agree with John there needs to be an upper bound (5 minutes?). It would also be great to try to sneak in some debugging to try to figure out what has the device open but that might be a bit harder.
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https://code.launchpad.net/~gjolly/livecd-rootfs/+git/livecd-rootfs/+merge/448708
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~gjolly/livecd-rootfs:ubuntu-cpc/device_busy into livecd-rootfs:ubuntu/master.