crypto: sun8i-ss - test error before assigning

The first thing we should do after dma_map_single() is to test the
result.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c

@@ -420,15 +420,15 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
 	}
 
 	addr_pad = dma_map_single(ss->dev, pad, j * 4, DMA_TO_DEVICE);
-	rctx->t_src[i].addr = addr_pad;
-	rctx->t_src[i].len = j;
-	rctx->t_dst[i].addr = addr_res;
-	rctx->t_dst[i].len = digestsize / 4;
 	if (dma_mapping_error(ss->dev, addr_pad)) {
 		dev_err(ss->dev, "DMA error on padding SG\n");
 		err = -EINVAL;
 		goto theend;
 	}
+	rctx->t_src[i].addr = addr_pad;
+	rctx->t_src[i].len = j;
+	rctx->t_dst[i].addr = addr_res;
+	rctx->t_dst[i].len = digestsize / 4;
 
 	err = sun8i_ss_run_hash_task(ss, rctx, crypto_tfm_alg_name(areq->base.tfm));