LU-6340 lnet: LNet startup script fix

LU-6340 lnet: LNet startup script fix

When starting up LNet via the startup script, check if the default
LNet yaml configuration file is present, if it is, then make sure
to use "lnetctl lnet configure" to bring up LNet instead of
"lctl network up".  The latter configures networks and routes
defined in the modparams, while the former does not, since the
configuration defined in the YAML file will be used.

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Change-Id: I1a05cba2a9a6b7a2179b541f1ea5db6d2e89b243
Reviewed-on: http://review.whamcloud.com/14000
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>