Attribute validation errors are logged twice

[Ihar Hrachyshka]

In neutron/api/v2/attributes.py, all validation functions debug-log any errors that occur inside them, and return the error message back to caller. In the end, those messages get into _validate_dict() function that also logs those messages, if any. Meaning, we'll get duplicate validation errors in debug logs for every validation failure.

Validation functions should not report those messages themselves, instead relying on caller to handle returned error messages as it sees fit.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/149853

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/149853
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=87f26929ee8e17d132c6d8c719e97e6795675caf
Submitter: Jenkins
Branch: master

commit 87f26929ee8e17d132c6d8c719e97e6795675caf
Author: Sandhya Dasu <email address hidden>
Date: Fri Jan 30 15:46:55 2015 -0500

    Remove duplicate logging of attribute validation errors

    Removed logging at top level function _validate_dict() and
    added logging at the lower level functions wherever necessary.

    Change-Id: I09ec62ef5998aea5735ff641166cbc5b469775e9
    Closes-bug: #1397310