[ALSA] usb audio: make quirk handling more readable, and fix commented-out code

usb audio contains useful  debugging code, protected by #if
0. Unfortunately, it will not compile because variable names changed;
fix it.

Dallas workaround is formatted in a way where it is not quite obvious
what is normal code and what is quirk. Reformat it to make it obvious.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/usb/usbaudio.c

@@ -1427,8 +1427,8 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	subs->cur_audiofmt = fmt;
 
 #if 0
-	printk("setting done: format = %d, rate = %d, channels = %d\n",
-	       fmt->format, fmt->rate, fmt->channels);
+	printk("setting done: format = %d, rate = %d..%d, channels = %d\n",
+	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
 	printk("  datapipe = 0x%0x, syncpipe = 0x%0x\n",
 	       subs->datapipe, subs->syncpipe);
 #endif
@@ -2468,11 +2468,12 @@ static int parse_audio_format_i_type(struct snd_usb_audio *chip, struct audiofor
 		}
 		break;
 	case USB_AUDIO_FORMAT_PCM8:
-		/* Dallas DS4201 workaround */
+		pcm_format = SNDRV_PCM_FORMAT_U8;
+
+		/* Dallas DS4201 workaround: it advertises U8 format, but really
+		   supports S8. */
 		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
 			pcm_format = SNDRV_PCM_FORMAT_S8;
-		else
-			pcm_format = SNDRV_PCM_FORMAT_U8;
 		break;
 	case USB_AUDIO_FORMAT_IEEE_FLOAT:
 		pcm_format = SNDRV_PCM_FORMAT_FLOAT_LE;