odd sg_request munging code in i2o post-2.6.12

Markus, any chance you could try to send in changes that deal with scsi internals through James SCSI tree?

You've sent some changes in that are rather odd:

- created a include/scsi/sg_request.h header that duplicates struct sg_request, an internal data structure of the sg driver. This approach gets easily out of sync.
- and poke into this data structure of an upper layer driver from a LLDD. That's a big "DON'T" While of the current drivers only SG uses that field it's open to any ULD, and you're also not supporting SG_IO on non-sg devices.
Besides that we are actively killing scsi_requests before 2.6.13, so you code will have to be remove by then.