LU-10391 lnet: allow lnet_connect() to use IPv6 addresses.

LU-10391 lnet: allow lnet_connect() to use IPv6 addresses.

Now that we can created and bind IPv6 sockets, connecting to them is
trivial.

Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I6032ea8a5937711922d9c318f72bc64c7020cc6d
Reviewed-on: https://review.whamcloud.com/37706
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Aurelien Degremont <degremoa@amazon.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>