Remove unused best_rd2 of handle_inter_mode

best_rd2 assigned a value which is never used.

Change-Id: If33ff7c0fc36476f6c6472b12faa9e64c54aa092
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index b16773c..970260e 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -9682,8 +9682,6 @@
       continue;
     }
 
-    int64_t best_rd2 = INT64_MAX;
-
     const RD_STATS backup_rd_stats = *rd_stats;
     // If !search_jnt_comp, we need to force mbmi->compound_idx = 1.
     for (comp_idx = 1; comp_idx >= !search_jnt_comp; --comp_idx) {
@@ -9963,10 +9961,6 @@
                  sizeof(best_blk_skip[0]) * xd->n4_h * xd->n4_w);
         }
 
-        if (tmp_rd < best_rd2) {
-          best_rd2 = tmp_rd;
-        }
-
         if (tmp_rd < ref_best_rd) {
           ref_best_rd = tmp_rd;
         }