LU-16707 scripts: make license-status more flexible

LU-16707 scripts: make license-status more flexible

Accept a path argument to restrict the search to a sub-tree.
By default, use the current directory. Also, fix some shellcheck
errors.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Iaddf0c22f8fed80947b0b511f9a56f6a35e0347b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55928
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>