sound: usb-audio: show sample format width in proc file

When listing the device's sample formats in the stream? proc file, the
sample format number itself is rather obscure, so we better show the
format width, too.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index c2db0f9..175c7d1 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2147,7 +2147,8 @@
 		fp = list_entry(p, struct audioformat, list);
 		snd_iprintf(buffer, "  Interface %d\n", fp->iface);
 		snd_iprintf(buffer, "    Altset %d\n", fp->altsetting);
-		snd_iprintf(buffer, "    Format: %#x\n", fp->format);
+		snd_iprintf(buffer, "    Format: %#x (%d bits)\n",
+			    fp->format, snd_pcm_format_width(fp->format));
 		snd_iprintf(buffer, "    Channels: %d\n", fp->channels);
 		snd_iprintf(buffer, "    Endpoint: %d %s (%s)\n",
 			    fp->endpoint & USB_ENDPOINT_NUMBER_MASK,