Silence a compiler warning

Change-Id: I130f748c076a1642f12b95051dab19bfdac5b855
diff --git a/av1/common/reconinter.c b/av1/common/reconinter.c
index c0c21ce..34e31b4 100644
--- a/av1/common/reconinter.c
+++ b/av1/common/reconinter.c
@@ -682,6 +682,9 @@
                         comp_data, mi->mbmi.sb_type, h, w);
 #endif  // CONFIG_SUPERTX
 #endif  // CONFIG_AOM_HIGHBITDEPTH
+#if CONFIG_COMPOUND_SEGMENT
+  (void)plane;
+#endif  // CONFIG_COMPOUND_SEGMENT
 }
 #endif  // CONFIG_EXT_INTER