Remove updateLFU() in dbOverwrite().

src/db.c

@@ -187,9 +187,6 @@ void dbOverwrite(redisDb *db, robj *key, robj *val) {
         int saved_lru = old->lru;
         dictReplace(db->dict, key->ptr, val);
         val->lru = saved_lru;
-        /* LFU should be not only copied but also updated
-         * when a key is overwritten. */
-        updateLFU(val);
     } else {
         dictReplace(db->dict, key->ptr, val);
     }