audio: Add some fall through comments

Static code analysers expect these comments for case statements without
a break statement.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: malc <av1474@comtv.ru>

audio/audio.c

diff --git a/audio/audio.c b/audio/audio.c
index 5fff6de..398763f 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -585,17 +585,20 @@
     switch (as->fmt) {
     case AUD_FMT_S8:
         sign = 1;
+        /* fall through */
     case AUD_FMT_U8:
         break;
 
     case AUD_FMT_S16:
         sign = 1;
+        /* fall through */
     case AUD_FMT_U16:
         bits = 16;
         break;
 
     case AUD_FMT_S32:
         sign = 1;
+        /* fall through */
     case AUD_FMT_U32:
         bits = 32;
         break;

audio/esdaudio.c

diff --git a/audio/esdaudio.c b/audio/esdaudio.c
index bd6e1cc..eea9cce 100644
--- a/audio/esdaudio.c
+++ b/audio/esdaudio.c
@@ -201,7 +201,7 @@
     case AUD_FMT_S32:
     case AUD_FMT_U32:
         dolog ("Will use 16 instead of 32 bit samples\n");
-
+        /* fall through */
     case AUD_FMT_S16:
     case AUD_FMT_U16:
     deffmt: