dma_map_sg return 0 on error, in case of error return -EIO.

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Christophe Kerello <redacted>
Cc: Cai Huoqing <cai.huoqing@linux.dev>
Cc: linux-mtd@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
---
  drivers/mtd/nand/raw/stm32_fmc2_nand.c | 8 +++++---
  1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/stm32_fmc2_nand.c b/drivers/mtd/nand/raw/stm32_fmc2_nand.c
index 87c1c7dd97eb..a0c825af19fa 100644
--- a/drivers/mtd/nand/raw/stm32_fmc2_nand.c
+++ b/drivers/mtd/nand/raw/stm32_fmc2_nand.c

@@ -862,8 +862,8 @@ static int stm32_fmc2_nfc_xfer(struct nand_chip *chip, const u8 *buf,
  
  	ret = dma_map_sg(nfc->dev, nfc->dma_data_sg.sgl,
  			 eccsteps, dma_data_dir);
-	if (ret < 0)
-		return ret;
+	if (!ret)
+		return -EIO;
  
  	desc_data = dmaengine_prep_slave_sg(dma_ch, nfc->dma_data_sg.sgl,
  					    eccsteps, dma_transfer_dir,

@@ -893,8 +893,10 @@ static int stm32_fmc2_nfc_xfer(struct nand_chip *chip, const u8 *buf,
  
  		ret = dma_map_sg(nfc->dev, nfc->dma_ecc_sg.sgl,
  				 eccsteps, dma_data_dir);
-		if (ret < 0)
+		if (!ret) {
+			ret = -EIO;
  			goto err_unmap_data;
+		}
  
  		desc_ecc = dmaengine_prep_slave_sg(nfc->dma_ecc_ch,
  						   nfc->dma_ecc_sg.sgl,