Fix compiling under -Werror=missing-field-initializers
Fix compiling under -Werror=missing-field-initializers

Summary:
MyRocks build is broken because they are using "-Werror=missing-field-initializers"
We should fix that by explicitly passing these arguments

Test Plan: Build MyRocks

Reviewers: sdong, yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D64161

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