Windows: AFSCommonWrite do not leak SectionObjectResource

If the write request is neither an extending write nor a non-cached
write and (liStartingByte.QuadPart + ulByteCount) >=
pFcb->Header.FileSize.QuadPart, then the SectionObjectResource pointer
will be leaked.  Instead release it before retrying.

Reviewed-on: http://gerrit.openafs.org/9888
Reviewed-by: Peter Scott <pscott@kerneldrivers.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Rod Widdowson <rdw@steadingsoftware.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit d1577c80bb8f6752b775a64af68649b648c659d9)

Change-Id: I77a248a13ccd8e2fe887f96ef820228b3a78b168
Reviewed-on: http://gerrit.openafs.org/9894
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>