ALSA: aloop: Remove redundant platform_set_drvdata()

Commit 0998d06310 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/aloop.c

@@ -1183,7 +1183,6 @@ static int loopback_probe(struct platform_device *devptr)
 static int loopback_remove(struct platform_device *devptr)
 {
 	snd_card_free(platform_get_drvdata(devptr));
-	platform_set_drvdata(devptr, NULL);
 	return 0;
 }