LU-17460 lnet: support IPv6 for link state

LU-17460 lnet: support IPv6 for link state

The LNet layer montiors the state of the underlying TCP
connection. Currently it only supports network interfaces
setup with IPv4 addresses. Update to handle IPv6 setups.

Test-Parameters: trivial testlist=sanity-lnet
Change-Id: I249e9591d5f637112f6bd862cd0f928a555af229
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53761
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>