ide-scsi: merge idescsi_input_buffers() and idescsi_output_buffers()

* Merge idescsi_input_buffers() and idescsi_output_buffers()
  into ide_scsi_io_buffers() helper.

While at it:

* Log device name instead of driver name on error.

* Use xfer_func_t.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>