Cinder netapp driver - Insufficient privileges gathering stats

* Detailed bug description:

 Cinder-volume module is spamming the log /var/log/cinder/cinder-volume.log with these messages:

2017-03-16 07:36:30.013 5410 ERROR cinder.volume.drivers.netapp.dataontap.performance.perf_cmode [req-edbef337-f895-4997-8c9e-dc269b7a0d55 - - - - -] Could not get utilization counters from node ESJC-DSNT-SN01P
2017-03-16 07:36:30.013 5410 ERROR cinder.volume.drivers.netapp.dataontap.performance.perf_cmode Traceback (most recent call last):
2017-03-16 07:36:30.013 5410 ERROR cinder.volume.drivers.netapp.dataontap.performance.perf_cmode File "/usr/lib/python2.7/dist-packages/cinder/volume/drivers/netapp/dataontap/performance/
....
....
2017-03-16 07:36:30.013 5410 ERROR cinder.volume.drivers.netapp.dataontap.performance.perf_cmode raise NaApiError(code, msg)
2017-03-16 07:36:30.013 5410 ERROR cinder.volume.drivers.netapp.dataontap.performance.perf_cmode NaApiError: NetApp API failed. Reason - 13003:Insufficient privileges: user 'ost-jc2' does not have read access to this resource
2017-03-16 07:36:30.013 5410 ERROR cinder.volume.drivers.netapp.dataontap.performance.perf_cmode

* Steps to reproduce:

 - Configure NFS backend for cinder services on Mitaka (Mirantis 9.1) using cinder_netapp FUel plugin [2]

 - Create the netapp user required for this integration using netapp documentation [3]

 - Start cinder services

 [2] https://github.com/openstack/fuel-plugin-cinder-netapp

 [3] http://netapp.github.io/openstack-deploy-ops-guide/mitaka/content/cinder.fas.configuration.html#cinder.cdot.account_permissions

Expected results:

 No errors are show in the /var/log/cinder/cinder-volume.log

Actual result:

 Log /var/log/cinder/cinder-volume.log being spammed with previous indicated errors.

Reproducibility:

 No action is needed. Log display the error on a rate of 1 per minute.

Workaround:

 None

* Impact:

 Cinder volume log get full of improper error messages.

* Description of the environment:
- Operation system: Unbuntu 14.04 trusty (MOS 9.1)
- Versions of components: cinder versions 2:8.1.0-6~u14.04+mos14
- Reference architecture: cinder using NFS as backend (netapp driver)
- Network model: N/A
- Related projects installed: N/A

* Additional information:

 After reporting this problem to NetApp support, they said is a known bug and patch is now released [4]

 Problem is that the patch seems to apply only to Ocata, maybe nobody else report it with Mitaka yet.

[4] https://review.openstack.org/#/c/433251/1