LU-8191 lnet: convert functions in utils to static

LU-8191 lnet: convert functions in utils to static

Static analysis shows that a number of functions
could be made static. This patch declares several
functions in various LNet utils and lnetconfig to
static.

In LNet selftest (lst), one unused function was
removed entirely. Some declarations were moved to
made static.

Lustre-change: https://review.whamcloud.com/51427
Lustre-commit: d9cd9992b9e04bfad1ebd755f78d3e96850eaa32

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Ia4528281b3c87d77e46abb95f47ab0bdc72168c0
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54619
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>