Log successful AddFile
Log successful AddFile

Summary: Log successful AddFile

Test Plan: visually check LOG file

Reviewers: yiwu, andrewkr, lightmark, sdong

Reviewed By: sdong

Subscribers: andrewkr, jkedgar, dhruba

Differential Revision: https://reviews.facebook.net/D65019

Andymic/rocksdb,SunguckLee/RocksDB,wat-ze-hex/rocksdb,wenduo/rocksdb,wenduo/rocksdb,Andymic/rocksdb,bbiao/rocksdb,facebook/rocksdb,SunguckLee/RocksDB,facebook/rocksdb,wat-ze-hex/rocksdb,Andymic/rocksdb,vmx/rocksdb,facebook/rocksdb,tsheasha/rocksdb,facebook/rocksdb,vmx/rocksdb,bbiao/rocksdb,wat-ze-hex/rocksdb,SunguckLee/RocksDB,SunguckLee/RocksDB,SunguckLee/RocksDB,SunguckLee/RocksDB,tsheasha/rocksdb,bbiao/rocksdb,facebook/rocksdb,tsheasha/rocksdb,Andymic/rocksdb,wat-ze-hex/rocksdb,Andymic/rocksdb,wat-ze-hex/rocksdb,SunguckLee/RocksDB,SunguckLee/RocksDB,bbiao/rocksdb,tsheasha/rocksdb,vmx/rocksdb,wenduo/rocksdb,Andymic/rocksdb,Andymic/rocksdb,wenduo/rocksdb,bbiao/rocksdb,facebook/rocksdb,tsheasha/rocksdb,vmx/rocksdb,wenduo/rocksdb,wat-ze-hex/rocksdb,wenduo/rocksdb,wat-ze-hex/rocksdb,wenduo/rocksdb,bbiao/rocksdb,tsheasha/rocksdb,facebook/rocksdb,Andymic/rocksdb,vmx/rocksdb,tsheasha/rocksdb,wat-ze-hex/rocksdb,vmx/rocksdb,wenduo/rocksdb,vmx/rocksdb,vmx/rocksdb,facebook/rocksdb,bbiao/rocksdb,tsheasha/rocksdb,bbiao/rocksdb