quartz: Check allocation failure and clear memory inDSound Renderer

[Felix Nawothnig]

Dmitry Timoshkov wrote:
>> However, note that NULL is not always all binary zero in memory. :)
> I don't believe it's true since NULL is defined as (void *)0.

Actually it may aswell be just 0 in C. Just in C++ it's defined to be 
(void *)0. But even with just 0 an assignment/compare/whatever will get 
you an implicit typecast which makes the compiler generate any necessary 
conversion.

See http://c-faq.com/null/

Felix