OSS: soundcard: locking bug in sound_ioctl()

We shouldn't return directly here because we're still holding the
&soundcard_mutex.

This bug goes all the way back to the start of git.  It's strange that
no one has complained about it as a runtime bug.

CC: stable@kernel.org
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/oss/soundcard.c

@@ -391,11 +391,11 @@ static long sound_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case SND_DEV_DSP:
 	case SND_DEV_DSP16:
 	case SND_DEV_AUDIO:
-		return audio_ioctl(dev, file, cmd, p);
+		ret = audio_ioctl(dev, file, cmd, p);
 		break;
 
 	case SND_DEV_MIDIN:
-		return MIDIbuf_ioctl(dev, file, cmd, p);
+		ret = MIDIbuf_ioctl(dev, file, cmd, p);
 		break;
 
 	}