Deduplicate some INFO and AUDIT level messages

I'm trying to debug a problem where the last thing in the logs is
"Starting instance...".  Unfortunately this occurs twice in the same
source file, so it's hard to figure out a priori which log statement
it came from.  Audit and info messages don't disambiguate their
function/line number, all you get is the logger name like:

2014-04-06 19:51:01.871 8288 AUDIT
  nova.compute.manager [req-...] [instance: ...] Starting instance...

I think it doesn't hurt to to make sure all logs at this level are
unique, even if upstream were to log the function (see [1]).  Most
duplicate LOG.info and LOG.audit level messages are in separate files
so we can disambiguate by the name, but there are a few that overlap.

For reference, the less-then-perfect but useful check I used was:
 $ grep -r 'LOG.audit' * | sed 's/:\s*/ /' | sort -k1 | uniq -f1 -c

[1] https://review.openstack.org/#/c/85638/

Change-Id: If1ff573ffed1d12fcadfbdfd3365aae68a5fb977
Merge "Deduplicate some INFO and AUDIT level messages"