crypto: stm32/hash - avoid error if maxburst not defined

dma-maxburst is an optional value and must not return
error in case of dma not used (or max-burst not defined).
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/stm32/stm32-hash.c

@@ -1413,18 +1413,19 @@ MODULE_DEVICE_TABLE(of, stm32_hash_of_match);
 static int stm32_hash_get_of_match(struct stm32_hash_dev *hdev,
 				   struct device *dev)
 {
-	int err;
-
 	hdev->pdata = of_device_get_match_data(dev);
 	if (!hdev->pdata) {
 		dev_err(dev, "no compatible OF match\n");
 		return -EINVAL;
 	}
 
-	err = of_property_read_u32(dev->of_node, "dma-maxburst",
-				   &hdev->dma_maxburst);
+	if (of_property_read_u32(dev->of_node, "dma-maxburst",
+				 &hdev->dma_maxburst)) {
+		dev_info(dev, "dma-maxburst not specified, using 0\n");
+		hdev->dma_maxburst = 0;
+	}
 
-	return err;
+	return 0;
 }
 
 static int stm32_hash_probe(struct platform_device *pdev)