LU-18391 lnet: Revert nid hash for gnilnd

LU-18391 lnet: Revert nid hash for gnilnd

Using hash_long() method for gnilnd apparently results in performance
degradation. It is not understood why this is, but for now revert to
the sum-by-multiplication of nid bytes method for gnilnd.

Test-Parameters: trivial
HPE-bug-id: LUS-11675
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I781658afb41e4c528d0d6d3aa3f73cbb928b9478
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56771
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>