avcodec/utils: Better check for channels in av_get_audio_frame_duration()

Fixes integer overflow
Fixes: 0c2625f236ced104d402b4a03c0d65c7/asan_generic_274e1ce_5990_9314e7a67c26aecf011b178ade9f217c.avi

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/utils.c

@@ -3067,7 +3067,7 @@ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)
                 return frame_bytes * 8 / bps;
         }
 
-        if (ch > 0) {
+        if (ch > 0 && ch < INT_MAX/16) {
             /* calc from frame_bytes and channels */
             switch (id) {
             case AV_CODEC_ID_ADPCM_AFC: