IB/mlx4: Set bad_wr for invalid send opcode

If the opcode of a work request exceeds the range of valid opcodes,
return the pointer to the offending work request.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/mlx4/qp.c

@@ -1884,6 +1884,7 @@ int mlx4_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 		wmb();
 
 		if (wr->opcode < 0 || wr->opcode >= ARRAY_SIZE(mlx4_ib_opcode)) {
+			*bad_wr = wr;
 			err = -EINVAL;
 			goto out;
 		}