Removing unused tbd struct member.

Change-Id: I07f7aea60ef7b9904f67e12eb5b2bfeb7348a454
diff --git a/vpx/internal/vpx_codec_internal.h b/vpx/internal/vpx_codec_internal.h
index a7716d1..0f5ce3d 100644
--- a/vpx/internal/vpx_codec_internal.h
+++ b/vpx/internal/vpx_codec_internal.h
@@ -347,7 +347,6 @@
     vpx_codec_priv_cb_pair_t    put_slice_cb;
   } dec;
   struct {
-    int                         tbd;
     struct vpx_fixed_buf        cx_data_dst_buf;
     unsigned int                cx_data_pad_before;
     unsigned int                cx_data_pad_after;