drivers' vendor_passthru should log all exceptions

[Ruby Loo]

Since the drivers' vendor_passthru are async. calls, any exceptions raised by them won't be handled. So all exceptions, even non-Ironic exceptions should be logged.

If there is common code, maybe move it to the base class.

This is a followup to a comment in https://review.openstack.org/#/c/122224/3/ironic/drivers/modules/agent.py.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/129298

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/129298
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=4bfae01ed04104f56b62c2844eabe2c151742a56
Submitter: Jenkins
Branch: master

commit 4bfae01ed04104f56b62c2844eabe2c151742a56
Author: Sam Betts <email address hidden>
Date: Fri Oct 17 13:52:00 2014 +0100

    Add logging to driver vendor_passthru functions

    Since the drivers' vendor_passthru are async. calls, any exceptions
    raised by them won't be handled. So all exceptions, even non-Ironic
    exceptions should be logged.

    This patch adds a decorator that can be used to wrap passthru function
    calls and ensure that any exceptions get logged correctly, also adds
    unit tests to ensure decorators functionality.

    Change-Id: I17006611fd59d5f4dc78fdaefdf802e9fb7caff2
    Implements: blueprint extended-vendor-passthru
    Closes-Bug: 1372979