Remove fixed TODO (#10241)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10241

Reviewed By: gitbw95

Differential Revision: D37369726

Pulled By: jay-zhuang

fbshipit-source-id: 1e94f0e2433aee42e9871043fa434291ce948eac

db/db_impl/db_impl_compaction_flush.cc

@@ -3802,11 +3802,6 @@ void DBImpl::GetSnapshotContext(
 
 Status DBImpl::WaitForCompact(bool wait_unscheduled) {
   // Wait until the compaction completes
-
-  // TODO: a bug here. This function actually does not necessarily
-  // wait for compact. It actually waits for scheduled compaction
-  // OR flush to finish.
-
   InstrumentedMutexLock l(&mutex_);
   while ((bg_bottom_compaction_scheduled_ || bg_compaction_scheduled_ ||
           bg_flush_scheduled_ ||