IB/mlx4: Fix opcode returned in RDMA read completion

Current code has a cut-and-paste error and returns IB_WC_SEND when it
should return IB_WC_RDMA_READ.
Signed-off-by: NVu Pham <vu@mellanox.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/mlx4/cq.c

@@ -389,7 +389,7 @@ static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq,
 			wc->opcode    = IB_WC_SEND;
 			break;
 		case MLX4_OPCODE_RDMA_READ:
-			wc->opcode    = IB_WC_SEND;
+			wc->opcode    = IB_WC_RDMA_READ;
 			wc->byte_len  = be32_to_cpu(cqe->byte_cnt);
 			break;
 		case MLX4_OPCODE_ATOMIC_CS: