ide: add calling add_boot_device_patch in bootindex setter function

On this way, we can assure the new bootindex take effect
during vm rebooting. Meanwhile set the initial value of
bootindex to -1.

Because ide devcies's unit property maybe
do not initialize when set_bootindex function is called,
so that we don't know its suffix. So we have to save the
call add_boot_device_path() on ide realize/init function.
When we want to change bootindex during vm rebooting, we
can call it in setter function.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Reviewed-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/ide/qdev.c

@@ -219,6 +219,10 @@ static void ide_dev_set_bootindex(Object *obj, Visitor *v, void *opaque,
     /* change bootindex to a new one */
     d->conf.bootindex = boot_index;
 
+    if (d->unit != -1) {
+        add_boot_device_path(d->conf.bootindex, &d->qdev,
+                             d->unit ? "/disk@1" : "/disk@0");
+    }
 out:
     if (local_err) {
         error_propagate(errp, local_err);
@@ -230,6 +234,7 @@ static void ide_dev_instance_init(Object *obj)
     object_property_add(obj, "bootindex", "int32",
                         ide_dev_get_bootindex,
                         ide_dev_set_bootindex, NULL, NULL, NULL);
+    object_property_set_int(obj, -1, "bootindex", NULL);
 }
 
 static int ide_hd_initfn(IDEDevice *dev)