drm_hwcomposer: Fix check commit script to ignore case and extra spaces
Job 93709 [1] failed with missing committer sign-off. Ayan has their committer string set to "Ayan kumar halder ayan.halder@arm.com", and the Signed-off-by line on the commit was "Signed-off-by: Ayan Kumar Halder ayan.halder@arm.com". So grep did what we asked it to do and did not find the SoB since the case was incorrect.
This patch changes to case-insensitive search and while we're at it, trims excess whitespace from both the commit body and the committer/author name.
Finally, I've improved the error message so it's hopefully more clear why things fail in the future.
[1]- https://gitlab.freedesktop.org/ayan.halder/drm-hwcomposer/-/jobs/93709
Signed-off-by: Sean Paul seanpaul@chromium.org