cifsd: fix a precedence bug in parse_dacl()

The shift has higher precedence than mask so this doesn't work as
intended.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>