A few fixes for ext-inter

* When wedge and compound-segment are disabled, we don't use
  compound_type_cdf, but it still gets copied around, averaged, etc.
  It's slightly nicer to avoid that when it isn't necessary.

* Fix an anomaly with cb4x4: We had (schematically)
  'if (bsize < 8X8 && CB4X4)', which is backwards when compared to
  other similar conditions elsewhere in the code.
  Change this to 'if (bsize < 8X8 && !CB4X4)" to match other code.

Change-Id: If802cf4f305c30cd642d0d5dd6610b547b52a027
diff --git a/av1/decoder/decodemv.c b/av1/decoder/decodemv.c
index 848772b..3a3e071 100644
--- a/av1/decoder/decodemv.c
+++ b/av1/decoder/decodemv.c
@@ -2347,7 +2347,7 @@
   }
 
 #if CONFIG_EXT_INTER
-  if ((bsize < BLOCK_8X8 && unify_bsize) ||
+  if ((bsize < BLOCK_8X8 && !unify_bsize) ||
       (mbmi->mode != ZEROMV && mbmi->mode != ZERO_ZEROMV))
 #else
   if ((bsize < BLOCK_8X8 && !unify_bsize) || mbmi->mode != ZEROMV)