mfd: twl4030-audio: Remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <[e-mail]>
Acked-by: Lee Jones <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/twl4030-audio.c

···
 		ret = -ENODEV;
 	}
 
-	if (ret) {
-		platform_set_drvdata(pdev, NULL);
+	if (ret)
 		twl4030_audio_dev = NULL;
-	}
 
 	return ret;
 }
···
 static int twl4030_audio_remove(struct platform_device *pdev)
 {
 	mfd_remove_devices(&pdev->dev);
-	platform_set_drvdata(pdev, NULL);
 	twl4030_audio_dev = NULL;
 
 	return 0;