LU-17235 o2iblnd: adding alias ib interface causes crash

LU-17235 o2iblnd: adding alias ib interface causes crash

Commit 09c6e2b872 (LU-16836) causes o2iblnd startup routine to crash
when alias ib interface is used:

        ifconfig ib0:0 10.1.0.52 up
        modprobe lnet
        lnetctl lnet configure
        lnetctl net add --net o2ib --if ib0:0

Fix the code which attempts to set the NI status on startup to deal
with the case when corresponding net_device is not found gracefully.

Test-Parameters: trivial testlist=sanity-lnet
Fixes: 09c6e2b872 ("LU-16836 lnet: ensure dev notification")
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: Iaef9280a10f27ac28b872d9f4bc119c4d459ef40
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/52894
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: Shuichi Ihara <sihara@ddn.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>