Windows: Set Server Prefs recalc immediately

Windows: Set Server Prefs recalc immediately

When processing the set server preferences pioctl call cm_RankServer()
to update the server preference value reported by "getserverprefs"
in addition to cm_ChangeRankVolume() or cm_ChangeRankCellVLServer().

Change-Id: Iacd8d30865286c39a7cc02e2f659b8c684f8f4a4
Reviewed-on: http://gerrit.openafs.org/8328
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>