smb3: fix access denied on change notify request to some servers

read permission, not just read attributes permission, is required
on the directory.

See MS-SMB2 (protocol specification) section 3.3.5.19.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> # v5.6+
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>