LU-18572 lnet: Uninitialized var in lnet_peer_add

LU-18572 lnet: Uninitialized var in lnet_peer_add

This is a regression introduced in the b2_15 port of

Lustre-change: https://review.whamcloud.com/50106
Lustre-commit: aacb16191a72bc6db1155030849efb0d6971a572

In b2_15, lnet_peer_add() takes an lnet_nid_t nid argument, but the
backport uses an uninitalized large nid variable in various places.
This results in incorrect behavior.

HPE-bug-id: LUS-12633
Test-Parameters: trivial
Fixes: b341288179 ("LU-14668 lnet: Lock primary NID logic")
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I6b9ca501bac97d40fd193b2c36874f632582714c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57494
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>