Remove superfluous except/re-raise

This exception code catches all exceptions, and then always raises them
again.

More interestingly, it uses excutils.save_and_reraise_exception
incorrectly (outside a `with` statement), which triggers the pylint test
designed to catch exactly this.

Change-Id: Iab9d69944cbae5257682ac65ff2b8fba3ef7017e
Merge "Remove superfluous except/re-raise"