LU-17000 lnet: fix various bugs in lib-move.c

LU-17000 lnet: fix various bugs in lib-move.c

In lnet_select_peer_ni, best_lpni_is_preferred is often written
to before being immediately overwritten.

Addresses-Coverity-ID: 397646 ("Unused value")
Addresses-Coverity-ID: 397434 ("Unused value")

Both LNetPut and LNetGet were not freeing msg under certain failure
conditions. This leaks a small amount of memory each time it occurs.

Addresses-Coverity-ID: 397644 ("Resource leak")
Addresses-Coverity-ID: 397133 ("Resource leak")

Fix potential null dereference in lnet_find_best_ni_on_local_net
when best_lp gets defined by best_net doesn't.

Addresses-Coverity-ID: 397568 ("Explicit null dereferenced")

lnet_post_send_locked has an un-needed null check, since every path
leading to that block of code must dereference ni anyway.

Addresses-Coverity-ID: 397278 ("Dereference before null check")

In the other usage of msg_peerrtrcredit, it is accessed under
lpni_lock. Change the second usage to also be accessed under this
lock.

Addresses-Coverity-ID: 397606 ("Data race condition")

Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I4012f407b10d0c9644535d49cce83a6c95d3d22d
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51876
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>