Remove duplicated variables in EXT_INTER

Introduced by merge commit 141f7a9

Change-Id: Idd68e09a6cd925d97466eabebe0e4905b5031340
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 3dfa2ee..a3929ef 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -9527,9 +9527,6 @@
         best_mbmode.mode = ZEROMV;
 #if CONFIG_EXT_INTER
     } else {
-      const MV_REFERENCE_FRAME refs[2] = { best_mbmode.ref_frame[0],
-                                           best_mbmode.ref_frame[1] };
-
       if (frame_mv[NEAREST_NEARESTMV][refs[0]].as_int ==
               best_mbmode.mv[0].as_int &&
           frame_mv[NEAREST_NEARESTMV][refs[1]].as_int ==