migration: send total time in QMP at "completed" stage

The "completed" stage sets total_time but not has_total_time and
thus it is not sent via QMP reply (but sent via HMP nevertheless)

Signed-off-by: Pawit Pornkitprasan <p.pawit@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

migration.c

@@ -231,6 +231,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
 
         info->has_status = true;
         info->status = g_strdup("completed");
+        info->has_total_time = true;
         info->total_time = s->total_time;
         info->has_downtime = true;
         info->downtime = s->downtime;