Provider drivers who override this definition started
seeing a failure due to a typo. For example:
W0237: [Parameter 'new_loadbalncer' has been renamed to
'new_loadbalancer' in overridden 'MyProviderDriver.
loadbalancer_update' method (arguments-renamed)
While we just updated .pylintrc to ignore the error,
might as well fix the typo.
Change-Id: I28e210605d2d8bc06bc99844c92b538568dbac45