LU-16763 tests: add more logging to run-llog.sh

LU-16763 tests: add more logging to run-llog.sh

Add more logging to run-llog.sh. At the same time, add SPDX text
and fix some minor shellcheck warnings.

Test-Parameters: trivial testlist=sanity env=ONLY=60a,ONLY_REPEAT=10
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I317fac7b872be53a1094022cfcd7d130b4c79c0a
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50719
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>