Initialize PartitionToWriteId (#14536)

Author: qyryq

ydb/public/lib/ydb_cli/commands/topic_workload/topic_workload_writer.h

@@ -76,7 +76,7 @@ namespace NYdb {
             TInstant StartTimestamp;
 
             std::vector<std::shared_ptr<TTopicWorkloadWriterProducer>> Producers;
-            ui64 PartitionToWriteId;
+            ui64 PartitionToWriteId = 0;
 
             std::shared_ptr<std::atomic<bool>> Closed;
             std::shared_ptr<TTopicWorkloadStatsCollector> StatsCollector;