part-handler has missing import for errno

[Angus Salkeld]

errno is used but not imported:

        except OSError as e:
            if e.errno != errno.EEXIST:
                raise

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/24392

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/24392
Committed: http://github.com/openstack/heat/commit/89005a04e72b553ea76b28d3694cc2a3c069feec
Submitter: Jenkins
Branch: master

commit 89005a04e72b553ea76b28d3694cc2a3c069feec
Author: Angus Salkeld <email address hidden>
Date: Thu Mar 14 12:25:12 2013 +1100

    part-handler: add missing import

    errno is used in the excption but not imported.

    bug 1154887
    Change-Id: I1c2961f08824d919ed2483a0a9cf54c50862f354