LU-16509 lnet: quash memcpy WARN_ONCE false positive

LU-16509 lnet: quash memcpy WARN_ONCE false positive

Linux v6.1-rc1-4-g6f7630b1b5bc
  fortify: Capture __bos() results in const temp var

In lnet_peer_push_event() the memcpy triggers a WARN_ONCE
due to the flexible array at the end of
struct lnet_ping_info contained in struct lnet_ping_buffer

Use unsafe_memcpy() to avoid this false positive warning.

Test-Parameters: trivial
HPE-bug-id: LUS-11455
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I4aa8f38678cd1522004d98b58a3f440d8a38589c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49801
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Patrick Farrell <pfarrell@whamcloud.com>