nvme-rdma: fix nvme_rdma_queue_is_ready

Now that we don't abuse the cmd field in struct request for nvme command
passthrough this function needs to be converted to the proper accessor
as well.

Fixes: d49187e97e ("nvme: introduce struct nvme_request")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index f587af3..34e5648 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1422,7 +1422,7 @@
 		struct request *rq)
 {
 	if (unlikely(!test_bit(NVME_RDMA_Q_LIVE, &queue->flags))) {
-		struct nvme_command *cmd = (struct nvme_command *)rq->cmd;
+		struct nvme_command *cmd = nvme_req(rq)->cmd;
 
 		if (rq->cmd_type != REQ_TYPE_DRV_PRIV ||
 		    cmd->common.opcode != nvme_fabrics_command ||