migration: Define VMSTATE_INSTANCE_ID_ANY

Define the new macro VMSTATE_INSTANCE_ID_ANY for callers who wants to
auto-generate the vmstate instance ID.  Previously it was hard coded
as -1 instead of this macro.  It helps to change this default value in
the follow up patches.  No functional change.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
index 375cb6abe9..f2c3a7f309 100644
--- a/hw/intc/apic_common.c
+++ b/hw/intc/apic_common.c
@@ -284,7 +284,7 @@ static void apic_common_realize(DeviceState *dev, Error **errp)
     }
 
     if (s->legacy_instance_id) {
-        instance_id = -1;
+        instance_id = VMSTATE_INSTANCE_ID_ANY;
     }
     vmstate_register_with_alias_id(NULL, instance_id, &vmstate_apic_common,
                                    s, -1, 0, NULL);