spi: fsl-dspi: Fix memory leak

The memory allocated for chip is not freed anywhere.
Convert to use devm_kzalloc to fix the memory leak.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-fsl-dspi.c

@@ -342,7 +342,8 @@ static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 	/* Only alloc on first setup */
 	chip = spi_get_ctldata(spi);
 	if (chip == NULL) {
-		chip = kcalloc(1, sizeof(struct chip_data), GFP_KERNEL);
+		chip = devm_kzalloc(&spi->dev, sizeof(struct chip_data),
+				    GFP_KERNEL);
 		if (!chip)
 			return -ENOMEM;
 	}
@@ -353,7 +354,6 @@ static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 		fmsz = spi->bits_per_word - 1;
 	} else {
 		pr_err("Invalid wordsize\n");
-		kfree(chip);
 		return -ENODEV;
 	}