LU-10391 lnet: Convert ping to support 16-bytes address

LU-10391 lnet: Convert ping to support 16-bytes address

Now that ksocknal can send hello messages with 16-byte address, we can
change lnet_send_ping() to ping hosts with large-address nids.

Note that this doesn't change the addresses in the ping message sent,
only the sending and receiving of the message.

Test-Parameters: trivial
Test-Parameters: serverversion=2.12 serverdistro=el7.9 testlist=runtests
Test-Parameters: clientversion=2.12 testlist=runtests
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I6f591c2f053698876195575c71da42f64788637e