mmc: mvsdio: Fix dma_unmap_sg() nents value

The dma_unmap_sg() functions should be called with the same nents as the
dma_map_sg(), not the value the map function returned.

Fixes: 236caa7 ("mmc: SDIO driver for Marvell SoCs")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: Thomas-fourier

drivers/mmc/host/mvsdio.c

@@ -292,7 +292,7 @@ static u32 mvsd_finish_data(struct mvsd_host *host, struct mmc_data *data,
 		host->pio_ptr = NULL;
 		host->pio_size = 0;
 	} else {
-		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->sg_frags,
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
 			     mmc_get_dma_dir(data));
 	}