clean up usb descriptors in example

examples/device/msc_dual_lun/src/usb_descriptors.c

@@ -34,7 +34,9 @@
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) )
 
-//------------- Device Descriptors -------------//
+//--------------------------------------------------------------------+
+// Device Descriptors
+//--------------------------------------------------------------------+
 tusb_desc_device_t const desc_device =
 {
     .bLength            = sizeof(tusb_desc_device_t),
@@ -56,7 +58,17 @@ tusb_desc_device_t const desc_device =
     .bNumConfigurations = 0x01
 };
 
-//------------- Configuration Descriptor -------------//
+// Invoked when received GET DEVICE DESCRIPTOR
+// Application return pointer to descriptor
+uint8_t const * tud_descriptor_device_cb(void)
+{
+  return (uint8_t const *) &desc_device;
+}
+
+//--------------------------------------------------------------------+
+// Configuration Descriptor
+//--------------------------------------------------------------------+
+
 enum
 {
   ITF_NUM_MSC,
@@ -82,13 +94,6 @@ uint8_t const desc_configuration[] =
   TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 0, EPNUM_MSC, 0x80 | EPNUM_MSC, (CFG_TUSB_RHPORT0_MODE & OPT_MODE_HIGH_SPEED) ? 512 : 64),
 };
 
-// Invoked when received GET DEVICE DESCRIPTOR
-// Application return pointer to descriptor
-uint8_t const * tud_descriptor_device_cb(void)
-{
-  return (uint8_t const *) &desc_device;
-}
-
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
@@ -98,7 +103,9 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
   return desc_configuration;
 }
 
-//------------- String Descriptors -------------//
+//--------------------------------------------------------------------+
+// String Descriptors
+//--------------------------------------------------------------------+
 
 // array of pointer to string descriptors
 char const* string_desc_arr [] =