Fix on compiling error when CONFIG_BVCOST_UPDATE is off

Fix on compiling error when CONFIG_BVCOST_UPDATE is off

For issue #141.
diff --git a/av1/encoder/encoder.h b/av1/encoder/encoder.h
index da7347c..e60ca3b 100644
--- a/av1/encoder/encoder.h
+++ b/av1/encoder/encoder.h
@@ -2741,7 +2741,7 @@
   /*!
    * Tables to calculate IntraBC MV cost.
    */
-#if !CONFIG_FLEX_MVRES || !CONFIG_BVCOST_UPDATE
+#if !CONFIG_FLEX_MVRES && !CONFIG_BVCOST_UPDATE
   IntraBCMVCosts dv_costs;
 #endif