Windows: cm_BkgDaemon should not do cm_SyncOp's job

Windows: cm_BkgDaemon should not do cm_SyncOp's job

cm_SyncOp is designed to synchronize operations among multiple
threads.  The background daemon threads should not filter requests
based upon cm_SyncOp states.  Doing so is racy and does not produce
better performance.

Change-Id: Ifeafd55da6e02807ed4cc3c3f2b6f1de4df2a87f
Reviewed-on: http://gerrit.openafs.org/5119
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>