usb: gadget: f_uac2: 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.
Acked-by: NJaswinder Singh <jaswinder.singh@linaro.org>
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_uac2.c

@@ -456,8 +456,6 @@ static int snd_uac2_remove(struct platform_device *pdev)
 {
 	struct snd_card *card = platform_get_drvdata(pdev);
 
-	platform_set_drvdata(pdev, NULL);
-
 	if (card)
 		return snd_card_free(card);