SOUND: fix race in device_create

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

sound/core/sound.c

@@ -259,8 +259,9 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
 		return minor;
 	}
 	snd_minors[minor] = preg;
-	preg->dev = device_create(sound_class, device, MKDEV(major, minor),
-				  "%s", name);
+	preg->dev = device_create_drvdata(sound_class, device,
+					  MKDEV(major, minor),
+					  private_data, "%s", name);
 	if (IS_ERR(preg->dev)) {
 		snd_minors[minor] = NULL;
 		mutex_unlock(&sound_mutex);
@@ -269,9 +270,6 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
 		return minor;
 	}
 
-	if (preg->dev)
-		dev_set_drvdata(preg->dev, private_data);
-
 	mutex_unlock(&sound_mutex);
 	return 0;
 }