Fix name conflict in delete_shceduler_test and db_sst_test

Summary: delete_scheduler_test and db_sst_test share a same directory name, causing possible fails on both tests when running in parallel. Fixed by changing directory name.

Test Plan: Run the two tests in parallel: `parallel -u ./{} ::: delete_scheduler_test db_sst_test`

Reviewers: sdong, andrewkr

Reviewed By: sdong, andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59529

util/delete_scheduler_test.cc

@@ -24,9 +24,9 @@ namespace rocksdb {
 class DeleteSchedulerTest : public testing::Test {
  public:
   DeleteSchedulerTest() : env_(Env::Default()) {
-    dummy_files_dir_ = test::TmpDir(env_) + "/dummy_data_dir";
+    dummy_files_dir_ = test::TmpDir(env_) + "/delete_scheduler_dummy_data_dir";
     DestroyAndCreateDir(dummy_files_dir_);
-    trash_dir_ = test::TmpDir(env_) + "/trash";
+    trash_dir_ = test::TmpDir(env_) + "/delete_scheduler_trash";
     DestroyAndCreateDir(trash_dir_);
   }