Windows: out of order lock smb v3 locking

Windows: out of order lock smb v3 locking

Do not obtain the smb_rctLock after holding the cm_scache_t->rw
lock.

At most one hold is required in case of lock failure.  Obtain
it as the start of processing and drop it at the end if not required.

Reviewed-on: http://gerrit.openafs.org/4955
Tested-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
(cherry picked from commit da6c97678f530ca76334613e229337a75f94e297)

Change-Id: I6b530366c74fd45ba585fd7af4615a1dc96ac055
Reviewed-on: http://gerrit.openafs.org/4960
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>