As3525 wavpack_enc document some intentional switch fall through

Change-Id: I56bf439df2c05653d65f49238e886e4ef2291176

firmware/target/arm/as3525/audio-as3525.c

@@ -67,6 +67,7 @@ void audio_input_mux(int source, unsigned flags)
     {
         default:                        /* playback - no recording */
             source = AUDIO_SRC_PLAYBACK;
+        /*fallthrough*/
         case AUDIO_SRC_PLAYBACK:
             if (source != last_source)
             {

firmware/target/arm/as3525/debug-as3525.c

@@ -288,14 +288,19 @@ static bool dbg_btn(bool *done, int *x)
         {
             case DEBUG_CANCEL:
                 *done = true;
+                /*fallthrough*/
             case DEBUG_NEXT:
                 cont = false;
+                /*fallthrough*/
             case DEBUG_LEFT_JUSTIFY:
                 (*x) = 0;
                 sleep(HZ/5);
                 break;
             case DEBUG_LEFT_SCROLL:
                 (*x)--;
+                break;
+            default:
+                break;
         }
     }
     lcd_clear_display();
@@ -610,4 +615,4 @@ int get_cpu_voltage_setting(void)
 
     return value;
 }
-#endif /* HAVE_ADJUSTABLE_CPU_VOLTAGE */
+#endif /* HAVE_ADJUSTABLE_CPU_VOLTAGE */

lib/rbcodec/codecs/wavpack_enc.c

@@ -365,6 +365,7 @@ enum codec_status codec_run(void)
             if (!(data = ci->enc_encbuf_get_buffer(out_reqsize)))
                 continue;
             getbuf = GETBUF_PCM;
+            /*fallthrough*/
         case GETBUF_PCM:
             if (!ci->enc_pcmbuf_read(input_buffer + PCM_SAMP_PER_CHUNK,
                                      PCM_SAMP_PER_CHUNK))