Refactor compound_segment to try different segmentation masks

Change-Id: I7c992c9aae895aebcfb5c147cb179cf665c0ac10
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index a047a90..ab4e47e 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -1626,7 +1626,8 @@
       }
 #if CONFIG_COMPOUND_SEGMENT
       else if (mbmi->interinter_compound_data.type == COMPOUND_SEG) {
-        aom_write_bit(w, mbmi->interinter_compound_data.which);
+        aom_write_literal(w, mbmi->interinter_compound_data.mask_type,
+                          MAX_SEG_MASK_BITS);
       }
 #endif  // CONFIG_COMPOUND_SEGMENT
     }