Fix type passed to opus_packet_parse_impl().

The function takes an opus_int32 *, but we were passing the address
 of an int, which might not be the same.
This is only likely to affect platforms with a 16-bit int.

Author: Timothy B. Terriberry

src/opus_decoder.c

@@ -1297,7 +1297,7 @@ int opus_dred_decoder_ctl(OpusDREDDecoder *dred_dec, int request, ...)
 static int dred_find_payload(const unsigned char *data, opus_int32 len, const unsigned char **payload, int *dred_frame_offset)
 {
    const unsigned char *data0;
-   int len0;
+   opus_int32 len0;
    int frame = 0;
    int nb_frames;
    const unsigned char *frames[48];