tools/patchwork_gitlab_igt: Remove undocumented test handling

Minimal changes needed to strip them out. Tracking the last postmerge is not needed anymore and can be taken out later.

Arek's changes with drm/igt-gpu-tools#99 removes the need to handle the comparison so this script can just report the pipeline status to patchwork.

Signed-off-by: Petri Latvala petri.latvala@intel.com