spi: dw: Don't call kfree for memory allocated by devm_kzalloc

With devm_kzalloc, the memory is automatically freed when spi_device detach from
the bus.

Fixes: commit 43f627a (spi: dw: fix memory leak on error path)
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stabe@vger.kernel.org

drivers/spi/spi-dw.c

@@ -665,12 +665,6 @@ static int dw_spi_setup(struct spi_device *spi)
 	return 0;
 }
 
-static void dw_spi_cleanup(struct spi_device *spi)
-{
-	struct chip_data *chip = spi_get_ctldata(spi);
-	kfree(chip);
-}
-
 static int init_queue(struct dw_spi *dws)
 {
 	INIT_LIST_HEAD(&dws->queue);
@@ -800,7 +794,6 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
 	master->bus_num = dws->bus_num;
 	master->num_chipselect = dws->num_cs;
-	master->cleanup = dw_spi_cleanup;
 	master->setup = dw_spi_setup;
 	master->transfer = dw_spi_transfer;
 	master->max_speed_hz = dws->max_freq;