Windows: fix locking hierarchy in service

Windows: fix locking hierarchy in service

The smb username lock and the daemon global lock can be requested
while the scache dirlock is held if there are no free buffers
and the service is forced to claw back extents from the redirector.
Adjust the locking hierarchy accordingly.

Reviewed-on: http://gerrit.openafs.org/6000
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>
(cherry picked from commit 2fc9edc6e34ebef60413fad9a2af2aa73ea1681f)

Change-Id: I74e87494c1360c61812908e3b4fb012829f71cf3
Reviewed-on: http://gerrit.openafs.org/6805
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>