Server footprint ISO tests cannot find ISO

It appears that the generated ISO path+name is incorrect for the server ISOs:

+ ISO=/data/iso/ubuntu/trusty-server-amd64.iso
+ bsdtar -x -f /data/iso/ubuntu/trusty-server-amd64.iso -O ./.disk/info
+ sed s/[^(]*(\([0-9.]*\))/\1/
bsdtar: Error opening archive: Failed to open '/data/iso/ubuntu/trusty-server-amd64.iso'

Console output:
https://platform-qa-jenkins.ubuntu.com/view/server/job/ubuntu-trusty-server-amd64-iso-disk-footprint/1/console

This is because the server ISO download tests place the ISO under "/data/iso/ubuntu-server" and not "ubunut". The fix would be to change this file:

http://bazaar.launchpad.net/~canonical-platform-qa-jenkins/qa-jenkins-jobs/trunk/view/head:/jobs/iso-testing/jobs.yaml
481: ISO="/data/iso/{flavor}/{release}-{variant}-{arch}.iso"
to
481: ISO="/data/iso/{flavor}-{variant}/{release}-{variant}-{arch}.iso"

However, that would break (what appears to be) the working desktop ISO tests. We seem to need to get consistent with each of these tests somehow.