lavc/tscc: use reget_buffer.

The previous code would release the buffer and get it
immediately after, assuming the contents is the same.

libavcodec/tscc.c

@@ -79,12 +79,9 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
     int zret; // Zlib return code
     int ret, len = buf_size;
 
-    if(c->pic.data[0])
-            avctx->release_buffer(avctx, &c->pic);
-
     c->pic.reference = 3;
     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
-    if((ret = avctx->get_buffer(avctx, &c->pic)) < 0){
+    if((ret = avctx->reget_buffer(avctx, &c->pic)) < 0){
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;
     }