rxe: Invalid qp_num in WCE after placing qp in error state

["Walker, Benjamin" <benjamin.walker@xxxxxxxxx>]

Hi all,

When placing an RDMA qp into IBV_QPS_ERR via ibv_modify_qp while that qp has
many outstanding operations, the completion queue entries generated
corresponding to those operations have invalid values for both wr_id and qp_num
(-1). This is prior to destroying the qp and only occurs for rxe (testing from
userspace). When running on real hardware NICs the values are correct.

I'm on Linux 4.18.12-200.fc28.x86_64 with libibverbs 1.1.16.2.

Thanks,
Ben