LU-15446 lnet: Don't use pref NI for reserved portal

Don't use the preferred NI when sending traffic on the LNet reserved
portal. This allows local recovery pings to utilize any local NI as
source in the case where we do not have a multi-rail peer entry for
the local host. This is typically the case when MR is not being
configured statically (i.e. when discovery is being used for MR
configuration).

lnet_get_best_ni() was modified to include health values of the NIs
being compared in its debug output.

HPE-bug-id: LUS-10658
Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I38f5760bf034f698b7f44ffa89aa91c4f5d4b9ea
Reviewed-on: https://review.whamcloud.com/46078
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Andriy Skulysh <andriy.skulysh@hpe.com>
Reviewed-by: Alexey Lyashkov <alexey.lyashkov@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>