cifs: Fix cifsacl ACE mask for group and others.

A two line fix which I made while testing my prev fix with
cifsacl mode conversions seem to have gone missing in the final fix
that was submitted. This is that fix.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>