crypto: hisilicon/zip - fix the return value when device is busy

As before, when the ZIP device is too busy to creat a request, it will
return '-EBUSY'. But the crypto process think the '-EBUSY' means a
successful request and wait for its completion.

So replace '-EBUSY' with '-EAGAIN' to show crypto this request is failed.

Fixes: 62c455ca("crypto: hisilicon - add HiSilicon ZIP...")
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Reviewed-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/hisilicon/zip/zip_crypto.c

@@ -498,7 +498,7 @@ static struct hisi_zip_req *hisi_zip_create_req(struct acomp_req *req,
 	if (req_id >= req_q->size) {
 		write_unlock(&req_q->req_lock);
 		dev_dbg(&qp_ctx->qp->qm->pdev->dev, "req cache is full!\n");
-		return ERR_PTR(-EBUSY);
+		return ERR_PTR(-EAGAIN);
 	}
 	set_bit(req_id, req_q->req_bitmap);
 
@@ -564,6 +564,7 @@ static int hisi_zip_do_work(struct hisi_zip_req *req,
 	ret = hisi_qp_send(qp, &zip_sqe);
 	if (ret < 0) {
 		atomic64_inc(&dfx->send_busy_cnt);
+		ret = -EAGAIN;
 		dev_dbg_ratelimited(dev, "failed to send request!\n");
 		goto err_unmap_output;
 	}