nvme: fix error-handling for io_uring nvme-passthrough

Driver may return an error before submitting the command to the device.
Ensure that such error is propagated up.

Fixes: 456cba38 ("nvme: wire-up uring-cmd support for io-passthru on char-device.")
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/ioctl.c

@@ -510,10 +510,13 @@ static enum rq_end_io_ret nvme_uring_cmd_end_io(struct request *req,
 	struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
 
 	req->bio = pdu->bio;
-	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED) {
 		pdu->nvme_status = -EINTR;
-	else
+	} else {
 		pdu->nvme_status = nvme_req(req)->status;
+		if (!pdu->nvme_status)
+			pdu->nvme_status = blk_status_to_errno(err);
+	}
 	pdu->u.result = le64_to_cpu(nvme_req(req)->result.u64);
 
 	/*