[SCSI] qla2xxx: Fix crash during firmware dump procedure.

System crashes, in initiator mode operation, with
qla2xxx_copy_atioqueues() in stack trace when firmware dump is
attempted.

Check for atio_q_length alone does not indicate if atio_ring is
allocated, make explicit check of atio_ring to avoid the crash.

Applicable to ISP24xx, ISP25xx, ISP81xx & ISP83xx line of HBAs.
Signed-off-by: Arun Easi <arun.easi@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla2xxx/qla_dbg.c

@@ -402,7 +402,7 @@ qla2xxx_copy_atioqueues(struct qla_hw_data *ha, void *ptr,
 		void *ring;
 	} aq, *aqp;
 
-	if (!ha->tgt.atio_q_length)
+	if (!ha->tgt.atio_ring)
 		return ptr;
 
 	num_queues = 1;

drivers/scsi/qla2xxx/qla_init.c

@@ -1397,7 +1397,7 @@ qla2x00_alloc_fw_dump(scsi_qla_host_t *vha)
 			mq_size += ha->max_rsp_queues *
 			    (rsp->length * sizeof(response_t));
 		}
-		if (ha->tgt.atio_q_length)
+		if (ha->tgt.atio_ring)
 			mq_size += ha->tgt.atio_q_length * sizeof(request_t);
 		/* Allocate memory for Fibre Channel Event Buffer. */
 		if (!IS_QLA25XX(ha) && !IS_QLA81XX(ha) && !IS_QLA83XX(ha))