call_plugin_serialized_with_retry sleeps after final retry

[John Garbutt]

The retry logic in call_plugin_serialized_with_retry sleeps even after the final retry.

Also, the sleeps are not stubbed out in the unit test, so it causes the unit tests to run for longer than we need to.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/51608

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/51608
Committed: http://github.com/openstack/nova/commit/a8062f900445f9909a1425f0232e6b4176116925
Submitter: Jenkins
Branch: master

commit a8062f900445f9909a1425f0232e6b4176116925
Author: John Garbutt <email address hidden>
Date: Mon Oct 14 14:54:44 2013 +0100

    xenapi: removes sleep after final upload retry

    This change removes the sleep that happens after the final retry of
    uploading an image.

    This change also ensures the unit tests do not take too long by stubbing
    out time.sleep.

    Closes bug 1239707
    Change-Id: I16b6639e3231d41fa476218f406fa5b3abdfaf71