Update.

Update.

	* malloc/hooks.c (DEFAULT_CHECK_ACTION): Moved to malloc.c.
	(check_action): Likewise.
	When printing error messages, use malloc_printf_nc now instead of
	fiddling with the streams cancellation flag in every place.
	* malloc/malloc.c (DEFAULT_CHECK_ACTION): New definition.  Change
	default to 3.
	(check_action): New variable.
	(unlink): Print error message and eventually terminate in case list
	is corrupted.
	(malloc_printf_nc): New function.  Use it in _int_free.
	Change proposed by Arjan van de Ven.