sound: Remove unnecessary casts of private_data

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/isa/sb/sb8.c b/sound/isa/sb/sb8.c
index 81284a8..2259e3f 100644
--- a/sound/isa/sb/sb8.c
+++ b/sound/isa/sb/sb8.c
@@ -72,7 +72,7 @@
 
 static void snd_sb8_free(struct snd_card *card)
 {
-	struct snd_sb8 *acard = (struct snd_sb8 *)card->private_data;
+	struct snd_sb8 *acard = card->private_data;
 
 	if (acard == NULL)
 		return;