monitor: Convert do_set_link() to QObject, QError

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/net.h b/net.h
index 9f3c82f..b83f615 100644
--- a/net.h
+++ b/net.h
@@ -118,7 +118,7 @@
                         const char *default_model);
 
 void do_info_network(Monitor *mon);
-void do_set_link(Monitor *mon, const QDict *qdict);
+int do_set_link(Monitor *mon, const QDict *qdict, QObject **ret_data);
 
 /* NIC info */