Fix mismatch when dual_filter daala-ec both are on

BUG=aomedia:132

Change-Id: I5c3214ddbc97576a2e90a070f2bdccc15be50d65
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index edf0267..0d65a15 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -1091,9 +1091,15 @@
           (mbmi->ref_frame[1] > INTRA_FRAME &&
            has_subpel_mv_component(xd->mi[0], xd, dir + 2))) {
         const int ctx = av1_get_pred_context_switchable_interp(xd, dir);
+#if CONFIG_EC_MULTISYMBOL
+        aom_write_symbol(w, av1_switchable_interp_ind[mbmi->interp_filter[dir]],
+                         ec_ctx->switchable_interp_cdf[ctx],
+                         SWITCHABLE_FILTERS);
+#else
         av1_write_token(w, av1_switchable_interp_tree,
                         ec_ctx->switchable_interp_prob[ctx],
                         &switchable_interp_encodings[mbmi->interp_filter[dir]]);
+#endif
         ++cpi->interp_filter_selected[0][mbmi->interp_filter[dir]];
       }
     }