mergehook: handle larger reports and DRM giga-patch quirks better

mergehook: trim excessively long reports

In some cases, we can get a report over 1m chars in length, which we need to trim to be able to actually display them in gitlab. We can mostly thank the way DRM giga-patches are done for this... :\

skip duplicate checking on DRM giga-patches

These patches have hundreds or even thousands of patches all merged into one, so we were doing a comparison for every single one of them, and then reporting the entire giga-patch file list for every single one of them... So for example, 1000 files times 1000 patches times 100 characters for each, leading us to generating 100,000,000 character comments. Just skip on doing comparisons on these abhorrent beasts.

Fixes: KMAINT-1572

Signed-off-by: Jarod Wilson jarod@redhat.com