EC: Reduce unnecessary log when processing excess redundancy.

This is a follow-up of HDFS-16964. We now avoid stale replicas when dealing with redundancy. This may result in redundant replicas not being in the `nonExcess` set when we enter `BlockManager#chooseExcessRedundancyStriped` (because the datanode where the redundant replicas are located has not send FBR yet, so those replicas are filtered out and not added to the `nonExcess` set). A further result is that no excess storage type is selected and the log "excess types chosen for block..." is printed. When a failover occurs, a large number of datanodes become stale, which causes NameNodes to print a large number of unnecessary logs.
This issue needs to be fixed, otherwise the performance after failover will be affected.