Don't zero buffer if big enough (#13877)
Don't zero buffer if big enough (#13877)

Only append zeroed bytes when we don't have enough space anyway.
krisis/minio,balamurugana/minio,krisis/minio,vadmeste/minio,balamurugana/minio,minio/minio,minio/minio,donatello/minio,donatello/minio,vadmeste/minio