LU-7734 lnet: fix lnet_select_pathway()

LU-7734 lnet: fix lnet_select_pathway()

Fixed the selection algorithm to work properly with > 1 local
networks. The behavior now is to iterate through all interfaces
on all networks

Also removed the health variable from struct lnet_peer_net since
it's never used.

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Change-Id: Ib91748e80446585b6a9e1bc0f3af6894599d8aaa
Reviewed-on: http://review.whamcloud.com/20890
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Tested-by: Jenkins