LU-10391 lnet: update ping to handle multiple NIDs

The original lnet ping Netlink code was setup to handle the pre-MR
API. Update this code to handle the newer MR version of ping. This
unifies all ping handling under one system and it supports larger
NID handling for IPv6. The big change is now that we support
updating the key table we can report failed pings in a different
format than the successful pings.

Instead of using the Netlink API version flag test if the passed
in LNet processid is LNET_PID_LUSTRE to display a NID or PID for
the ping results. Also cleanup the memory for failed ping NID
list.

Test-Parameters: trivial testlist=sanity-lnet
Change-Id: I77a0e313bf2b7035e501726068fd45bb3a118d06
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49361


Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>