Clean ups and bug-fixes for filter_intra

Clean up: clean up unused entropy related arrays
Bug-fixes: resolve compiling errors when it is enabled with
entropy_stats and ext_skip

Change-Id: I2893e1b5c09e847fb4677f6e62709464208b76f8
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 4bae6af..880cedb 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -818,7 +818,7 @@
     if (mbmi->filter_intra_mode_info.use_filter_intra) {
       const FILTER_INTRA_MODE mode =
           mbmi->filter_intra_mode_info.filter_intra_mode;
-      aom_write_symbol(w, mode, xd->tile_ctx->filter_intra_mode_cdf[0],
+      aom_write_symbol(w, mode, xd->tile_ctx->filter_intra_mode_cdf,
                        FILTER_INTRA_MODES);
     }
   }