Apply suggestions from code review

Co-authored-by: Copilot <[email protected]>

Author: HiFiPhile

src/class/audio/audio_device.c

@@ -867,17 +867,17 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
 
     // Advance to next interface descriptor
     p_desc = tu_desc_next(p_desc);
-    while (p_desc_end - p_desc > 0 && tu_desc_type(p_desc) != TUSB_DESC_INTERFACE) {
+    while (tu_desc_in_bounds(p_desc, p_desc_end) && tu_desc_type(p_desc) != TUSB_DESC_INTERFACE) {
       p_desc = tu_desc_next(p_desc);
     }
 
     // Verify next interface is Audio Streaming (subclass 2), not MIDI Streaming (subclass 3)
-    if (p_desc_end - p_desc > 0) {
+    if (p_desc_end - p_desc >= (int)sizeof(tusb_desc_interface_t)) {
       tusb_desc_interface_t const *next_itf = (tusb_desc_interface_t const *) p_desc;
       TU_VERIFY(next_itf->bInterfaceClass == TUSB_CLASS_AUDIO &&
                 next_itf->bInterfaceSubClass == AUDIO_SUBCLASS_STREAMING, 0);
     } else {
-      // No further interface found
+      // No further interface found or not enough bytes for interface descriptor
       return 0;
     }
   }