ALSA: mips/sgio2audio: Remove redundant platform_set_drvdata()

Commit 0998d063 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Cc: Vivien Chappelier <vivien.chappelier@linux-mips.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/mips/sgio2audio.c

@@ -963,7 +963,6 @@ static int snd_sgio2audio_remove(struct platform_device *pdev)
 	struct snd_card *card = platform_get_drvdata(pdev);
 
 	snd_card_free(card);
-	platform_set_drvdata(pdev, NULL);
 	return 0;
 }