add missing default switch cases

platform/libusb/hci_transport_h2_libusb.c

@@ -434,6 +434,9 @@ static void handle_isochronous_data(uint8_t * buffer, uint16_t size){
                 packet_handler(HCI_SCO_DATA_PACKET, sco_buffer, sco_read_pos);
                 sco_state_machine_init();
                 break;
+			default:
+				btstack_assert(false);
+				break;
         }
     }
 }
@@ -1183,6 +1186,8 @@ static int usb_close(void){
                 doing_pollfds = 0;
             }
 
+            /* fall through */
+
         case LIB_USB_INTERFACE_CLAIMED:
             // Cancel all transfers, ignore warnings for this
             libusb_set_debug(NULL, LIBUSB_LOG_LEVEL_ERROR);
@@ -1281,11 +1286,20 @@ static int usb_close(void){
 #endif
             log_info("Libusb shutdown complete");
 
+			/* fall through */
+
         case LIB_USB_DEVICE_OPENDED:
             libusb_close(handle);
 
+			/* fall through */
+
         case LIB_USB_OPENED:
             libusb_exit(NULL);
+            break;
+
+		default:
+			btstack_assert(false);
+			break;
     }
 
     libusb_state = LIB_USB_CLOSED;

src/btstack_base64_decoder.c

@@ -42,6 +42,7 @@
  */
 
 #include "btstack_base64_decoder.h"
+#include "btstack_debug.h"
 #include <string.h>
 
 /**
@@ -119,6 +120,9 @@ int  btstack_base64_decoder_process_byte(btstack_base64_decoder_t * context, uin
         case 99:
             result = BTSTACK_BASE64_DECODER_INVALID;
             break;
+		default:
+			btstack_assert(false);
+			break;
     }
     return result;
 }

src/btstack_slip.c

@@ -215,6 +215,9 @@ void btstack_slip_decoder_process(uint8_t input){
                     break;
             }
             break;
+		default:
+			btstack_assert(false);
+			break;
     }
 }
 

src/hci_transport_h5.c

@@ -704,6 +704,9 @@ static void hci_transport_h5_process_frame(uint16_t frame_size){
                     // reset inactvitiy timer
                     hci_transport_inactivity_timer_set();
                     break;
+				default:
+					// invalid packet type,  ignore
+					break;
             }
 
             break;