scsi: qla1280: Remove set but not used variable in qla1280_done()

This addresses the following gcc warning with "make W=1":

drivers/scsi/qla1280.c: In function ‘qla1280_done’:
drivers/scsi/qla1280.c:1244:19: warning: variable ‘lun’ set but not used
[-Wunused-but-set-variable]
 1244 |  int bus, target, lun;
      |                   ^~~

Link: https://lore.kernel.org/r/20200907074518.2326360-2-yanaijie@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla1280.c

@@ -1241,7 +1241,7 @@ qla1280_done(struct scsi_qla_host *ha)
 {
 	struct srb *sp;
 	struct list_head *done_q;
-	int bus, target, lun;
+	int bus, target;
 	struct scsi_cmnd *cmd;
 
 	ENTER("qla1280_done");
@@ -1256,7 +1256,6 @@ qla1280_done(struct scsi_qla_host *ha)
 		cmd = sp->cmd;
 		bus = SCSI_BUS_32(cmd);
 		target = SCSI_TCN_32(cmd);
-		lun = SCSI_LUN_32(cmd);
 
 		switch ((CMD_RESULT(cmd) >> 16)) {
 		case DID_RESET: