Windows: Strip out unused ModWriter Fastio code

The code is no longer used (the fcb->PagingIO resource is taken for
us by the modwriter) so we strip it out to save other making changes
and then remembering/discovering that this code isn't being used.

Reviewed-on: http://gerrit.openafs.org/10191
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 22d7c8461b16940c3606d63a0b7e232563871cd8)

Change-Id: I81c872810aecb3f123473e9d4a48f47727b0beb1
Reviewed-on: http://gerrit.openafs.org/10211
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: Hold Fcb Resource across CcPurgeSection

Now that the Fcb Resource and SectionObjectResource are held in
the FastIo pathway and the Trend Micro deadlock has been addressed
by holding a reference on the FileObject it is time to fix the
lock acquisition ordering.   For each CcPurgeSection call the
Fcb Resource will be held exclusive before the SectionObjectResource.

Reviewed-on: http://gerrit.openafs.org/10192
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 27311ca420c2ee29b38aa2994993cf24d7d769b1)

Change-Id: I263daaad723206c34f4ac72d47a902a94cc7b218
Reviewed-on: http://gerrit.openafs.org/10212
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>