qom: strdup() target property name on object_property_add_alias()

With this, object_property_add_alias() callers can safely free the
target property name, like what already happens with the 'name' argument
to all object_property_add*() functions.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

qom/object.c

@@ -1705,7 +1705,7 @@ void object_property_add_uint64_ptr(Object *obj, const char *name,
 
 typedef struct {
     Object *target_obj;
-    const char *target_name;
+    char *target_name;
 } AliasProperty;
 
 static void property_get_alias(Object *obj, struct Visitor *v, void *opaque,
@@ -1736,6 +1736,7 @@ static void property_release_alias(Object *obj, const char *name, void *opaque)
 {
     AliasProperty *prop = opaque;
 
+    g_free(prop->target_name);
     g_free(prop);
 }
 
@@ -1763,7 +1764,7 @@ void object_property_add_alias(Object *obj, const char *name,
 
     prop = g_malloc(sizeof(*prop));
     prop->target_obj = target_obj;
-    prop->target_name = target_name;
+    prop->target_name = g_strdup(target_name);
 
     op = object_property_add(obj, name, prop_type,
                              property_get_alias,