quartz: Fix some memory leaks in the file source

[Maarten Lankhorst]

Found with valgrind after running the filtergraph test.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.winehq.org/pipermail/wine-patches/attachments/20080404/a29d0749/attachment-0001.htm 
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: 0005-quartz-Fix-some-memory-leaks-in-file-source.txt
Url: http://www.winehq.org/pipermail/wine-patches/attachments/20080404/a29d0749/attachment-0001.txt