The DRAC driver's (pxe_drac) get_bios_config() vendor passthru method
raises an AttributeError exception. It no longer returns the current
BIOS configuration. This is a regression from stable/mitaka.
Triage found that get_bios_config() mistakenly treats the value returned
by python-dracclient's list_bios_settings() as containing named tuples.
When it calls the namedtuple _asdict() method, an AttributeError
exception is raised.
Revert get_bios_config()'s handling of the return value to use __dict__.
Remove the comment that is not consistent with the implementation.
Also revert the unit test case for a successful call to use mock to
create the return value. Use mock.NonCallableMock with an empty
specification (spec) to catch this type of bug in the future.
Change-Id: I94afaa72a1ef25efc1b622e29e3a92a5d27f1892
Closes-Bug: #1637671
6d6cf18f31