Bug#760060: autopkgtest: qemu runner fails with systemd

[Felix Geyer]

Package: autopkgtest
Version: 3.4

adt-virt-qemu checks the runlevel of the guest in make_auxverb() and expects
it to be 2.
systemd by default boots into runlevel 5 (aka graphical.target).

This makes the qemu runner error out with the following rather cryptic error message:
> adt-virt-qemu: DBG: execute-timeout: /tmp/adt-virt-qemu.69k6wvus/runcmd runlevel
> adt-virt-qemu: DBG: runlevel: exit 0, out "N 5
> ", err "None"
> qemu: terminating on signal 15 from pid 12301
> adt-virt-qemu: DBG: cleanup...
> <VirtSubproc>: failure: failed to connect to VM
> adt-run: DBG: bomb unexpected eof from the testbed

If it really cares about the runlevel it should probably accept everything from 2-5.

Cheers,
Felix