rgw: RGWBucket::sync() no longer duplicates datalog/bilog entries
RGWSI_BucketIndex_RADOS::handle_overwrite() is already writing the
datalog/bilog entries related to BUCKET_DATASYNC_DISABLED
RGWBucket::sync() calls handle_overwrite() indirectly from
bucket->put_info() when it writes the bucket instance with this new
BUCKET_DATASYNC_DISABLED flag, so RGWBucket::sync() shouldn't
duplicate those writes here