db/db_impl.cc: reduce scope of prefix_initialized

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>

db/db_impl.cc

@@ -3064,7 +3064,6 @@ Status DBImpl::DoCompactionWork(CompactionState* compact,
   assert(compact);
   compact->CleanupBatchBuffer();
   compact->CleanupMergedBuffer();
-  bool prefix_initialized = false;
 
   // Generate file_levels_ for compaction berfore making Iterator
   compact->compaction->GenerateFileLevels();
@@ -3149,6 +3148,7 @@ Status DBImpl::DoCompactionWork(CompactionState* compact,
     // 2) send value_buffer to compaction filter and alternate the values;
     // 3) merge value_buffer with ineligible_value_buffer;
     // 4) run the modified "compaction" using the old for loop.
+    bool prefix_initialized = false;
     shared_ptr<Iterator> backup_input(
         versions_->MakeInputIterator(compact->compaction));
     backup_input->SeekToFirst();