LU-11860 lnet: support config of LNDs with numeric intf name

LU-11860 lnet: support config of LNDs with numeric intf name

This patch adds support for the net configuration of LNDs that
have numeric interface name (PTL4LND, GNILND). The GNILND case has
already been treated with a specific fix (see patch a29eb587).

Signed-off-by: Gregoire Pichon <gregoire.pichon@bull.net>
Change-Id: I10556f9c78ec332bca3344990e509434f904ffc0
Reviewed-on: https://review.whamcloud.com/34028
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Chris Horn <hornc@cray.com>
Reviewed-by: Amir Shehata <ashehata@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>