crypto: hisilicon - fix missed error branch

If an error occurs in the process after the SGL is mapped
successfully, it need to unmap the SGL.

Otherwise, memory problems may occur.
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/hisilicon/sgl.c

@@ -225,7 +225,7 @@ hisi_acc_sg_buf_map_to_hw_sgl(struct device *dev,
 	dma_addr_t curr_sgl_dma = 0;
 	struct acc_hw_sge *curr_hw_sge;
 	struct scatterlist *sg;
-	int sg_n;
+	int sg_n, ret;
 
 	if (!dev || !sgl || !pool || !hw_sgl_dma || index >= pool->count)
 		return ERR_PTR(-EINVAL);
@@ -240,14 +240,15 @@ hisi_acc_sg_buf_map_to_hw_sgl(struct device *dev,
 
 	if (sg_n_mapped > pool->sge_nr) {
 		dev_err(dev, "the number of entries in input scatterlist is bigger than SGL pool setting.\n");
-		return ERR_PTR(-EINVAL);
+		ret = -EINVAL;
+		goto err_unmap;
 	}
 
 	curr_hw_sgl = acc_get_sgl(pool, index, &curr_sgl_dma);
 	if (IS_ERR(curr_hw_sgl)) {
 		dev_err(dev, "Get SGL error!\n");
-		dma_unmap_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
-		return ERR_PTR(-ENOMEM);
+		ret = -ENOMEM;
+		goto err_unmap;
 	}
 	curr_hw_sgl->entry_length_in_sgl = cpu_to_le16(pool->sge_nr);
 	curr_hw_sge = curr_hw_sgl->sge_entries;
@@ -262,6 +263,11 @@ hisi_acc_sg_buf_map_to_hw_sgl(struct device *dev,
 	*hw_sgl_dma = curr_sgl_dma;
 
 	return curr_hw_sgl;
+
+err_unmap:
+	dma_unmap_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
+
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(hisi_acc_sg_buf_map_to_hw_sgl);