Fix uninitilizeded SpecialEnv::time_elapse_only_sleep_

Summary: SpecialEnv::time_elapse_only_sleep_ is not initialized, which might cause some test failures. Fix it.

Test Plan: Run some unit tests. Since tests already broken. Might want to commit it sooner.

Reviewers: IslamAbdelRahman, yhchiang, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D50937

db/db_test_util.cc

@@ -18,6 +18,7 @@ SpecialEnv::SpecialEnv(Env* base)
       rnd_(301),
       sleep_counter_(this),
       addon_time_(0),
+      time_elapse_only_sleep_(false),
       no_sleep_(false) {
   delay_sstable_sync_.store(false, std::memory_order_release);
   drop_writes_.store(false, std::memory_order_release);