Windows: do not forget cm_SyncOpDone

If cm_SyncOp was called, then cm_SyncOpDone must be called.
By goto out of the loop, the cm_SyncOpDone call was skipped.

Reviewed-on: http://gerrit.openafs.org/11414
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit bcaaf4640d06c761b798c1eb2c82f81f21ec78d8)

Change-Id: Iafa0e3f5b552f7219a1be047d26fc40e238dc5d2
Reviewed-on: http://gerrit.openafs.org/11418
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>