xenapi: image upload does not need to propagate usage_agent key

[John Garbutt]

Bad use of system metadata means xenapi_use_agent key is never propagated to the snapshots.

However compute.api will automatically inherit all image properties that are saved into system metadata, so this logic can be removed.

[John Garbutt (johngarbutt)]

https://review.openstack.org/#/c/38637/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/38637
Committed: http://github.com/openstack/nova/commit/79420db5c9aa2d29c78058a38a82a5fa049bf1e8
Submitter: Jenkins
Branch: master

commit 79420db5c9aa2d29c78058a38a82a5fa049bf1e8
Author: John Garbutt <email address hidden>
Date: Thu Jul 25 15:36:24 2013 +0100

    xenapi: remove propagate xenapi_use_agent key

    The compute.api class will already propagate then xenapi_use_agent key
    when required, so we can remove the xenapi specific code that tries to
    propagate this value. The code did not correctly access the system
    metadata, would have failed to propagate the key anyway.

    Fixes bug 1204933
    Change-Id: Ib291a265318d80705129e565155d4250fd704b75