am 8d567480: Update open_data_source documentation to accurately reflect the correct return value on error.

Merge commit '8d567480b45a801a1955e4743c5eeae431d58f56'

* commit '8d567480b45a801a1955e4743c5eeae431d58f56':
  Update open_data_source documentation to accurately reflect the correct return value on error.