Remove the 'result' field of FrameWorkerData.

The 'result' field of FrameWorkerData is only set and used in the
frame_worker_hook() function. Therefore it just needs to be a local
variable in that function.

Change-Id: Id579e75964707429f8a88aef392a278f03491429

av1/av1_dx_iface.c

diff --git a/av1/av1_dx_iface.c b/av1/av1_dx_iface.c
index 5a0e918..d5d5a8d 100644
--- a/av1/av1_dx_iface.c
+++ b/av1/av1_dx_iface.c
@@ -342,16 +342,16 @@
   const uint8_t *data = frame_worker_data->data;
   (void)arg2;
 
-  frame_worker_data->result = av1_receive_compressed_data(
-      frame_worker_data->pbi, frame_worker_data->data_size, &data);
+  int result = av1_receive_compressed_data(frame_worker_data->pbi,
+                                           frame_worker_data->data_size, &data);
   frame_worker_data->data_end = data;
 
-  if (frame_worker_data->result != 0) {
+  if (result != 0) {
     // Check decode result in serial decode.
     frame_worker_data->pbi->cur_buf->buf.corrupted = 1;
     frame_worker_data->pbi->need_resync = 1;
   }
-  return !frame_worker_data->result;
+  return !result;
 }
 
 static aom_codec_err_t init_decoder(aom_codec_alg_priv_t *ctx) {

av1/decoder/dthread.h

diff --git a/av1/decoder/dthread.h b/av1/decoder/dthread.h
index 33d8900..9f854e0 100644
--- a/av1/decoder/dthread.h
+++ b/av1/decoder/dthread.h
@@ -39,7 +39,6 @@
   const uint8_t *data_end;
   size_t data_size;
   void *user_priv;
-  int result;
   int worker_id;
   int received_frame;