Windows: smb_FindShareCSCPolicy uses invalid registry key

Windows: smb_FindShareCSCPolicy uses invalid registry key

smb_FindShareCSCPolicy() ignored the error state of RegCreateKeyEx()
and would pass the uninitialized hkCSCPolicy to RegQueryValueEx()
and RegCloseKey().  While this did not produce invalid results, it
did result in unnecessary operations and exception handling within
the Win32 registry apis.

LICENSE MIT

Reviewed-on: http://gerrit.openafs.org/402
Tested-by: Asanka Herath <asanka@secure-endpoints.com>
Reviewed-by: Asanka Herath <asanka@secure-endpoints.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>