target: fix double unmap data sg in core_scsi3_emulate_pro_register_and_move()

Signed-off-by: tangwenji <tang.wenji@zte.com.cn>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_pr.c

@@ -3528,8 +3528,6 @@ after_iport_check:
 
 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
 
-	transport_kunmap_data_sg(cmd);
-
 	core_scsi3_put_pr_reg(dest_pr_reg);
 	return 0;
 out: