qom: Make object_child_foreach() safe for objects removal Current object_child_foreach() uses QTAILQ_FOREACH() to walk through children and that makes children removal from the callback impossible. This makes object_child_foreach() use QTAILQ_FOREACH_SAFE(). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Hu Tao <hutao@cn.fujitsu.com> Signed-off-by: Andreas Färber <afaerber@suse.de>