ALSA: sgio2audio: Improve a size determination in snd_sgio2audio_create()

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/mips/sgio2audio.c

@@ -840,7 +840,7 @@ static int snd_sgio2audio_create(struct snd_card *card,
 	if (!(readq(&mace->perif.audio.control) & AUDIO_CONTROL_CODEC_PRESENT))
 		return -ENOENT;
 
-	chip = kzalloc(sizeof(struct snd_sgio2audio), GFP_KERNEL);
+	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 	if (chip == NULL)
 		return -ENOMEM;