use encodefmt for usb audio

Reference: /n/atom/patch/applied/usbaudioencode
Date: Sat Apr 19 00:44:23 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/usb/audio/audio.c	Sat Apr 19 00:44:23 2014
+++ /sys/src/cmd/usb/audio/audio.c	Sat Apr 19 00:44:23 2014
@@ -32,9 +32,11 @@
 static void
 audio_endpoint(Dev *, Desc *dd)
 {
-	byte *b = (uchar*)&dd->data;
-	int n = dd->data.bLength;
-	char *hd;
+	byte *b;
+	int n;
+
+	b =  (uchar*)&dd->data;
+	n = dd->data.bLength;
 
 	switch(b[2]){
 	case 0x01:
@@ -72,11 +74,8 @@
 		}
 		break;
 	default:
-		if(usbdebug){
-			hd = hexstr(b, n);
-			fprint(2, "CS_INTERFACE: %s\n", hd);
-			free(hd);
-		}
+		if(usbdebug)
+			fprint(2, "CS_INTERFACE: %.*H\n", n, b);
 	}
 }
 
@@ -227,6 +226,7 @@
 		value[i] = 0;
 	fmtinstall('A', Aconv);
 	fmtinstall('U', Ufmt);
+	fmtinstall('H', encodefmt);
 	quotefmtinstall();
 
 	ARGBEGIN{
--- /sys/src/cmd/usb/audio/audiosub.c	Sat Apr 19 00:44:23 2014
+++ /sys/src/cmd/usb/audio/audiosub.c	Sat Apr 19 00:44:23 2014
@@ -227,9 +227,8 @@
 			}
 			break;
 		default:
-			hd = hexstr(bb, nb);
-			fprint(2, "audio control unknown: %s\n", hd);
-			free(hd);
+			fprint(2, "audio control unknown: %.*H\n", nb, bb);
+			break;
 		}
 		break;
 	case 2: // stream
@@ -281,20 +280,15 @@
 			aa->subframesize = b[5];
 			break;
 		default:
-			if(usbdebug){
-				hd = hexstr(bb, nb);
-				fprint(2, "audio stream unknown: %s\n", hd);
-				free(hd);
-			}
+			if(usbdebug)
+				fprint(2, "audio stream unknown: %.*H\n", nb, bb);
+			break;
 		}
 		break;
 	case 3: // midi
 	default:
-		if(usbdebug){
-			hd = hexstr(bb, nb);
-			fprint(2, "Unknown audio stream type: CS_INTERFACE: %s\n", hd);
-			free(hd);
-		}
+		if(usbdebug)
+			fprint(2, "Unknown audio stream type: CS_INTERFACE: %.*H\n", nb, bb);
+		break;
 	}
 }
-