target: Don't override EXTENDED_COPY xcopy_pt_cmd SCSI status code

target: Don't override EXTENDED_COPY xcopy_pt_cmd SCSI status code

This patch addresses a bug where a local EXTENDED_COPY WRITE or READ
backend I/O request would always return SAM_STAT_CHECK_CONDITION,
even if underlying xcopy_pt_cmd->se_cmd generated a different
SCSI status code.

ESX host environments expect to hit SAM_STAT_RESERVATION_CONFLICT
for certain scenarios, and SAM_STAT_CHECK_CONDITION results in
non-retriable status for these cases.

Tested on v4.1.y with ESX v5.5u2+ with local IBLOCK backend copy.

Reported-by: Nixon Vincent <[email protected]>
Tested-by: Nixon Vincent <[email protected]>
Cc: Nixon Vincent <[email protected]>
Tested-by: Dinesh Israni <[email protected]>
Signed-off-by: Dinesh Israni <[email protected]>
Cc: Dinesh Israni <[email protected]>
Cc: [email protected] # 3.14+
Signed-off-by: Nicholas Bellinger <[email protected]>