LU-17913 iokit: Fix lst.sh host mode

LU-17913 iokit: Fix lst.sh host mode

The ssh command used to get primary NIDs of each test node uses a
single quote. This prevents the LCTL variable from being expanded
so the command fails. Use double quotes around this command and
make sure we return an error (non-zero) status when we are unable
to determine primary NIDs of test nodes.

Test-Parameters: trivial testlist=sanity-lnet
Fixes: c265e1c7b0 ("LU-16861 obdfilter: Exclude quotes when getting NIDs")
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: Ic17d8a22baf93e205c6d7e12a0079f93222013e3
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55343
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>