ALSA: Fix a Oops bug in omap soc driver.

There will be a Oops or frequent underrun messages when playing music with
omap soc driver, this is because a data region is incorretly sized, other data
region will be overwriten when writing to this data region.
Signed-off-by: Stanley Miao <stanley.miao@windriver.com>
Acked-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Cc: stable@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/soc/omap/omap-pcm.c

@@ -233,7 +233,7 @@ static int omap_pcm_open(struct snd_pcm_substream *substream)
 	if (ret < 0)
 		goto out;
 
-	prtd = kzalloc(sizeof(prtd), GFP_KERNEL);
+	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 	if (prtd == NULL) {
 		ret = -ENOMEM;
 		goto out;