LU-17869 llapi: Fixed function header comments

Updated input parameter descriptions for
`llapi_layout_v2_sanity` and `llapi_layout_sanity` functions.

Test-parameters: trivial
Fixes: ee7dfc5ad1 ("LU-17025 llapi: Verify stripe pool name")
Signed-off-by: Rajeev Mishra <rajeevm@hpe.com>
Change-Id: I72f4973d8be70ad60d088ea0e18d1e961f01cd50
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55180
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>