RDMA/rtrs-clt: Use minimal max_send_sge when create qp

We use device limit max_send_sge, which is suboptimal for memory usage.
We don't need that much for User Con, 1 is enough. And for IO con,
sess->max_segments + 1 is enough

Link: https://lore.kernel.org/r/20210614090337.29557-3-jinpu.wang@ionos.com


Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>