LU-13029 lnet: fix asym routing with multi-hop

LU-13029 lnet: fix asym routing with multi-hop

When a system is setup with multi-hop routing the next-hop
gateway, one off the nodes, will not have an interface
on the remote network. The route should still be considered
alive even if lnet_avoid_asym_routing is set

The code sets a route to be multi-hop if the gateway it uses
does not have an NI on the remote net of the route. The underlying
assumption here is that routing configuration is correct

To aid in fault detection a warning message is printed out if
the route is set to be multi-hop but the route hop count is less
than 1.

Added a YAML field in the:
lnetctl route show -v
output to print the type of the route: single-hop or multi-hop.

Test-parameters: trivial

Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Change-Id: I0a96263e2903974ec50d46bd56e550cde7d86e8c
Reviewed-on: https://review.whamcloud.com/36914
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Doug Oucharek <dougso@me.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>