ntb: use correct mw_count function in ntb_tool and ntb_transport

After converting to the new API, both ntb_tool and ntb_transport are
using ntb_mw_count to iterate through ntb_peer_get_addr when they
should be using ntb_peer_mw_count.

This probably isn't an issue with the Intel and AMD drivers but
this will matter for any future driver with asymetric memory window
counts.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Fixes: 443b9a14 ("NTB: Alter MW API to support multi-ports devices")