cifs: clean up set_cifs_acl interfaces

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>