Windows: no side effects from AFSDbgLogMsg calls

Do not perform assignments or call side-effect resulting functions
as parameters to AFSDbgLogMsg.

Change-Id: I76eca3a82377543f4148d03af51a07886127b385
Reviewed-on: http://gerrit.openafs.org/9242
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>