scsi: target: Fix sense key for invalid EXTENDED COPY request

TCM fails to pass the following tests in libiscsi:

  SCSI.ExtendedCopy.DescrType
  SCSI.ExtendedCopy.DescrLimits
  SCSI.ExtendedCopy.ParamHdr
  SCSI.ExtendedCopy.ValidSegDescr
  SCSI.ExtendedCopy.ValidTgtDescr

The xcopy code always returns the same NOT READY sense key for all detected
errors. Change the sense key for invalid requests to ILLEGAL REQUEST, and
for aborted transfers to COPY ABORTED.

Link: https://lore.kernel.org/r/20210803145410.80147-3-s.samoylenko@yadro.com


Fixes: d877d727 ("target: Fix a deadlock between the XCOPY code and iSCSI session shutdown")
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>