LU-12375 scripts: Start lnet after opa

LU-12375 scripts: Start lnet after opa

Ensure ordering of lnet after opa for startup and lnet before opa on
shutdown.

Lustre-change: https://review.whamcloud.com/35032
Lustre-commit: 54adf45f2c73e542a2fcf3125781de791fac9c56

Signed-off-by: Nathaniel Clark <nclark@whamcloud.com>
Change-Id: I4c2cad2381349f866bdc08e2a81e3d8990d8752e
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-by: Artur Novik <anovik@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/35260
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>