Use the correct variable when fetching table properties.

Summary:
An uninitialized parameter was being passed into the call to fetch the table
properties during the compaction notification callbacks.

Test Plan:
Build it with myrocks and verify unit test passed.
Run unit tests.

Reviewers: rven, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D49635

db/db_impl.cc

@@ -1873,8 +1873,7 @@ void DBImpl::NotifyOnCompactionCompleted(
         info.input_files.push_back(fn);
         if (info.table_properties.count(fn) == 0) {
           std::shared_ptr<const TableProperties> tp;
-          std::string fname;
-          auto s = cfd->current()->GetTableProperties(&tp, fmd, &fname);
+          auto s = cfd->current()->GetTableProperties(&tp, fmd, &fn);
           if (s.ok()) {
             info.table_properties[fn] = tp;
           }