drivers/rtc/rtc-ds1305.c: remove unnecessary spi_set_drvdata()

The driver core clears the driver data to NULL after device_release or on
probe failure.  Thus, it is not needed to manually clear the device driver
data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ds1305.c

@@ -787,7 +787,6 @@ static int ds1305_remove(struct spi_device *spi)
 		cancel_work_sync(&ds1305->work);
 	}
 
-	spi_set_drvdata(spi, NULL);
 	return 0;
 }