LU-17062 lnet: Update lnet_peer_*_decref_locked usage

LU-17062 lnet: Update lnet_peer_*_decref_locked usage

Move decref's to occur after last reference to prevent
use after free.

Lustre-change: https://review.whamcloud.com/52184
Lustre-commit: 60cfceb8c59364f786b31ac36c2c245b9a1e495a

HPE-bug-id: LUS-11799
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I2382ece560039383f644b6aee73a9481d6bb5673
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/54904
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>