scsi: scsi_debug: Return failed value if error is injected

scsi: scsi_debug: Return failed value if error is injected

If a fail queuecommand error is injected, return the failed value defined
in the rule from queuecommand.

Make queuecommand return format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x1                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |   4    |  x32 | The queuecommand() return value we want               |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "1 1 0x12 0x1055" > ${error}

will make each INQUIRY command sent to that device return 0x1055
(SCSI_MLQUEUE_HOST_BUSY).

Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-6-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>