Blackfin SPI driver: tweak spi cleanup function to match newer kernel changes

Signed-off-by: Mike Frysinger <[e-mail]>
Signed-off-by: Bryan Wu <[e-mail]>
Cc: David Brownell <[e-mail]>

drivers/spi/spi_bfin5xx.c

···
  */
 static void cleanup(struct spi_device *spi)
 {
-	struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
+	struct chip_data *chip = spi_get_ctldata(spi);
 
 	kfree(chip);
 }