vhost-scsi: set the bootable value of channel/target/lun

At present, the target is valued boot_tpgt, In addition,
channel and lun both are 0 for bootable vhost-scsi device.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NBo Su <subo7@huawei.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi/vhost-scsi.c

@@ -251,6 +251,12 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
+    s->channel = 0;
+    s->lun = 0;
+    /* Note: we can also get the minimum tpgt from kernel */
+    s->target = vs->conf.boot_tpgt;
+
     error_setg(&s->migration_blocker,
             "vhost-scsi does not support migration");
     migrate_add_blocker(s->migration_blocker);