[autotest] Make run_suite reimaging job reporting backward-compatible

run_suite should tolerate suite jobs that contain just the one line for reimaging
jobs, as opposed to per-host reports.

BUG=chromium-os:22060
TEST=run_suite.py -m <old suite job id>

Change-Id: Ifabc6e98ccf96717a031be7f6c836d7a0b3c2f9d
Reviewed-on: https://gerrit.chromium.org/gerrit/26347
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Ready: Chris Masone <cmasone@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>
1 file changed