fash create doesn't fail when vnode count isn't passed in

[yunong]

[root@c53b592e-5818-4cea-96c7-d7bfa64684b8 (emy-10:manta0) /opt/smartdc/manta-deployment]# /opt/smartdc/manta-deployment/node_modules/.bin/fash create -v -p '2.moray.coal.joyent.us
3.moray.coal.joyent.us
4.moray.coal.joyent.us' -b leveldb -l /var/tmp/manta-ring
[root@c53b592e-5818-4cea-96c7-d7bfa64684b8 (emy-10:manta0) /opt/smartdc/manta-deployment]# ./node_modules/.bin/fash get_pnodes -l /var/tmp/manta-ring/ -b leveldb
{ jse_shortmsg: 'unable to load ring from db',
  jse_summary: 'unable to load ring from db: : Invalid argument: /var/tmp/manta-ring/: does not exist (create_if_missing is false)',
  jse_cause:
   { jse_shortmsg: '',
     jse_summary: ': Invalid argument: /var/tmp/manta-ring/: does not exist (create_if_missing is false)',
     jse_cause: [Error: Invalid argument: /var/tmp/manta-ring/: does not exist (create_if_missing is false)],
     message: ': Invalid argument: /var/tmp/manta-ring/: does not exist (create_if_missing is false)' },
  message: 'unable to load ring from db: : Invalid argument: /var/tmp/manta-ring/: does not exist (create_if_missing is false)' }