smb: server: correct value for smb_direct_max_fragmented_recv_size

smb: server: correct value for smb_direct_max_fragmented_recv_size

We should make it clear that we use this strange value
instead of hiding it in same code flow.

Note this value is mainly ignored currently,
as we do the calculation again with
the negotiated max_recv_size in smb_direct_prepare().
So this is only a cosmetic change in order to
avoid confusion.

In future we may change the logic and
adjust the number of recv buffers instead
of the max_fragmented_recv_size.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>