Fix build without supertx.

Change-Id: Ib60821487710f6cf06aaa8ddcbdd5487ba1cbe4f
diff --git a/vp10/encoder/encodeframe.c b/vp10/encoder/encodeframe.c
index c66be39..c6715ce 100644
--- a/vp10/encoder/encodeframe.c
+++ b/vp10/encoder/encodeframe.c
@@ -1654,7 +1654,9 @@
                                    totalrate_nocoef,
 #endif  // CONFIG_SUPERTX
                                    bsize, ctx, best_rd);
+#if CONFIG_SUPERTX
         assert(*totalrate_nocoef >= 0);
+#endif  // CONFIG_SUPERTX
       }
     } else {
       vp10_rd_pick_inter_mode_sub8x8(cpi, tile_data, x, mi_row, mi_col, rd_cost,
@@ -1662,7 +1664,9 @@
                                      totalrate_nocoef,
 #endif  // CONFIG_SUPERTX
                                      bsize, ctx, best_rd);
+#if CONFIG_SUPERTX
       assert(*totalrate_nocoef >= 0);
+#endif  // CONFIG_SUPERTX
     }
   }