mmc: of_mmc_spi: fix unused warning

drivers/mmc/host/of_mmc_spi.c: In function 'mmc_spi_get_pdata':
drivers/mmc/host/of_mmc_spi.c:77:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
  int ret = -EINVAL;
      ^
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/of_mmc_spi.c

@@ -74,7 +74,6 @@ struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
 	const u32 *voltage_ranges;
 	int num_ranges;
 	int i;
-	int ret = -EINVAL;
 
 	if (dev->platform_data || !np)
 		return dev->platform_data;
@@ -97,7 +96,6 @@ struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
 		mask = mmc_vddrange_to_ocrmask(be32_to_cpu(voltage_ranges[j]),
 					       be32_to_cpu(voltage_ranges[j + 1]));
 		if (!mask) {
-			ret = -EINVAL;
 			dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
 			goto err_ocr;
 		}