Windows: power management suspend/resume changes

Windows: power management suspend/resume changes

1. Call cm_UpdateIFInfo() for all power management events to force
   an update of the valid network interface count.

2. Ensure that regardless of which Suspend and Resume events are
   generated that the service only suspends once and resumes once.

Change-Id: If0c2fe5b6a18dd6b7ee01b511378cb78837efa3d
Reviewed-on: http://gerrit.openafs.org/11447
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>