audio: Add missing fall through comments

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190718193441.12490-1-sw@weilnetz.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

audio/audio.c

@@ -306,6 +306,7 @@ void audio_pcm_init_info (struct audio_pcm_info *info, struct audsettings *as)
 
     case AUDIO_FORMAT_S16:
         sign = 1;
+        /* fall through */
     case AUDIO_FORMAT_U16:
         bits = 16;
         shift = 1;
@@ -313,6 +314,7 @@ void audio_pcm_init_info (struct audio_pcm_info *info, struct audsettings *as)
 
     case AUDIO_FORMAT_S32:
         sign = 1;
+        /* fall through */
     case AUDIO_FORMAT_U32:
         bits = 32;
         shift = 2;