LU-8191 lnet: remove unused, fix non-static functions

LU-8191 lnet: remove unused, fix non-static functions

Static analysis shows that a number of functions
could be made static. This patch also declares
several functions in lnet static.

Lustre-change: https://review.whamcloud.com/51436
Lustre-commit: 43cbc93f1edc493e47fe5c4059bf0bae6a20c207

It is wrong to remove lnet_selftest_structure_assertion()
since it contained BUILD_BUGs used to ensure different LNet
Selftest versions can interoperate.

Add a dummy user for lnet_selftest_structure_assertion() in
LNet Selftest init. This should prevent analyzers from picking
this up as an unused function.

Lustre-change: https://review.whamcloud.com/54635
Lustre-commit: TBD (from ed2a2286d17a7d23b86a87094d1eb2abac8ea015)

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Ie1b49c5652553715cd9f96b56090d33a95e3b438
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54604
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>