Refactoring scsi_error to facilitate in synchronous REQUEST_SENSE

In motivation to abstract scsi_cmnd members and insulate drivers/transports from scsi_cmnd internals. The last place left was the REQUEST_SENSE sequence when done synchronous, by drivers.

Also all these drivers would do a use_sg==0 command invocation, preventing from doing cleanups on these drivers/transports. So this patchset is left-overs from Christoph's 2.6.18 cleanups.

In this patchset I have re-factored scsi_error to make it possible for drivers to use an abstract (easy to use, I hope) API for invoking a REQUEST_SENSE command. The API is declared in scsi/scsi_eh.h

[patch 1/5] scsi_error: code cleanup before refactoring of scsi_send_eh_cmnd()
Move some code around and add new fixtures here. So next patch is left a Mechanical breakup of code.

[patch 2/5] scsi_error: Refactoring scsi_error to facilitate in synchronous REQUEST_SENSE
Here new API is introduced in scsi/scsi_eh.h and mechanical move of code to the new functions.

[PATCH 3/5] usb: transport.c use scsi_eh API in REQUEST_SENSE execution
Use above API for drivers/usb/storage/transport.c. Now that last User of use_sg==0, we can do the USB storage cleanups.

[PATCH 4/5] NCR5380: Use scsi_eh API for REQUEST_SENSE invocation
All NCR5380 family of drivers used to send a REQUEST_SENSE command.

[PATCH 5/5] arm: fas216 Use scsi_eh API for REQUEST_SENSE invocation
drivers/scsi/arm/fas216.c need change also.

Please Test as much as possible, and report any problems/differences.

Boaz Harrosh