Fix bug in av1_tree_to_cdf_2D() macro.

Change-Id: Ic04e180b09745fab2230d05985770c41deea4fad
diff --git a/aom_dsp/prob.h b/aom_dsp/prob.h
index 63121e0..f0ea01b 100644
--- a/aom_dsp/prob.h
+++ b/aom_dsp/prob.h
@@ -117,7 +117,7 @@
     }                                           \
   } while (0)
 
-#define av1_tree_to_cdf_2D(tree, probs, cdf, u, v)     \
+#define av1_tree_to_cdf_2D(tree, probs, cdf, v, u)     \
   do {                                                 \
     int j;                                             \
     int i;                                             \