libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_mvref_common.c

 
 /*
  *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
@@ skipping 205 matching lines @@
 
       nearest_mv->as_int = bmi[2].as_mv[ref].as_int;
       for (n = 0; n < 2 + MAX_MV_REF_CANDIDATES; ++n)
         if (nearest_mv->as_int != candidates[n].as_int) {
           near_mv->as_int = candidates[n].as_int;
           break;
         }
       break;
     }
     default:
-      assert("Invalid block index.");
+      assert(0 && "Invalid block index.");
   }
 }