Retry on DBDeadLock affecting worker updates
Retry on DBDeadLock affecting worker updates

Some updates on the workers table are prone to race conditions,
leading to DB deadlocks.

For example, when creating a large amount of volumes simultaneously,
some of them may hang in "Creating" state due to this issue.

We'll perform some retries when db deadlocks occur.

Change-Id: Iae211acd619070405f84a84ea58e88723a5e9f9b
Closes-Bug: #1789106

openstack/cinder,openstack/cinder,mahak/cinder,mahak/cinder