no timeout parameter when execute ovs-vsctl in nova

[Yaguang Tang]

ovs-vsctl can fails or take a long time to return, it would be better to add a timeout parameter which neuturon has done.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/47788

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/47788
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=5d84150eeaaf8539686989c418e36e1877cef42e
Submitter: Jenkins
Branch: master

commit 5d84150eeaaf8539686989c418e36e1877cef42e
Author: Gary Kotton <email address hidden>
Date: Mon Sep 23 00:16:38 2013 -0700

    Add configurable 120s timeout ovs-vsctl calls

    By default, or with a secs of 0, ovs−vsctl waits forever for a response
    from the database. This option limits runtime to approximately 120 seconds.
    If the timeout expires, ovs−vsctl will exit with a SIGALRM signal. (A
    timeout would normally happen only if the database cannot be contacted,
    or if the system is overloaded.)

    The user can update the timeout by setting the ovs_vsctl_timeout
    configuration variable.

    DocImpact

    Closes-bug: 1229018

    Change-Id: Ica64ae98fb6162d2119021972127a82417d5ee7a