Fix doc build warnings so docs build clean

Tried for as minimal changes as possible.

example warning is:
manila/share/drivers/service_instance.py:docstring of
manila.share.drivers.service_instance.ServiceInstanceManager:5: ERROR: Unexpected indentation.

Change-Id: Ic3cce38ac555deaac4b80bc5eb0d8484bc92364f
Closes-Bug: 1379935
Merge "Fix doc build warnings so docs build clean"