LU-9633 lod: Add kernel doc style for lod (Part 2)

LU-9633 lod: Add kernel doc style for lod (Part 2)

This patch converts existing functional comments
to kernel doc style comments and removes '/**' for
comments which is not meant to be a kernel-doc comment

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I00844d369329541da28ef55f997fd295930db0c5
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/58604
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Anjus George <georgea@ornl.gov>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>