scsi: documentation: Corrections for struct updates

Update scsi_mid_low_api.rst for changes to struct scsi_host and
struct scsi_cmnd.

struct scsi_host:

 - no_async_abort is gone

 - drop sh_list w/ no replacement

 - change my_devices to __devices

struct scsi_cmnd:

 - removed 'done' (now in struct scsi_driver); use scsi_done() or
   scsi_done_direct() callbacks

 - change previous request_bufflen to scsi_bufflen()

 - change previous use_sg field to scsi_dma_map() or scsi_sg_count()

 - change previous request_buffer field to reference to 'usg_sg' text

[mkp: removed more obsolete stuff]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20241221212539.1314560-1-rdunlap@infradead.org


Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>