RDMA/mana_ib: Fix DSCP value in modify QP

Convert the traffic_class in GRH to a DSCP value as required by the HW.

Fixes: e095405 ("RDMA/mana_ib: Modify QP state")
Signed-off-by: Shiraz Saleem <shirazsaleem@microsoft.com>
Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
Link: https://patch.msgid.link/1752143085-4169-1-git-send-email-kotaranov@linux.microsoft.com
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: Shiraz Saleem

drivers/infiniband/hw/mana/qp.c

@@ -772,7 +772,7 @@ static int mana_ib_gd_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		req.ah_attr.dest_port = ROCE_V2_UDP_DPORT;
 		req.ah_attr.src_port = rdma_get_udp_sport(attr->ah_attr.grh.flow_label,
 							  ibqp->qp_num, attr->dest_qp_num);
-		req.ah_attr.traffic_class = attr->ah_attr.grh.traffic_class;
+		req.ah_attr.traffic_class = attr->ah_attr.grh.traffic_class >> 2;
 		req.ah_attr.hop_limit = attr->ah_attr.grh.hop_limit;
 	}