OVS with DPDK fails to start after compute reboot due to not mounted hugepages

[Mikhail Chernik]

Environment: MOS 9.2 snapshot #688, OVS+DPDK

Description:

Node deployment does not save hugepages configuration, so after compute reboot only KVM hugepages are mounted. This prevents OpenVSwitch+DPDK from starting after reboot.

http://paste.openstack.org/show/594568/

Steps to reproduce:
1. Deploy a cluster with DPDK configured on compute
2. Check that ovs-vswitchd process is running and there is no errors in its log file
3. Reboot node
4. Repeat step 2

Actual result:
ovs-vswitchd process is not running, log file contains error messages:
2017-01-11T14:21:11.808Z|00002|daemon_unix|ERR|fork child died before signaling startup (killed (Aborted), core dumped)
2017-01-11T14:21:25.301Z|00002|daemon_unix|ERR|fork child died before signaling startup (killed (Aborted), core dumped)