[Bug 36360] valgrind shows several leaks in dxdiagn/tests/provider.c

https://bugs.winehq.org/show_bug.cgi?id=36360

--- Comment #1 from Sven  ---
The first leak is due to IAMFilterData_ParseFilterData being called in
dxdiagn/provider.c, which internally calls FM2_ReadFilterData, which in turn
needs a method such as FM2_DeleteRegFilter to clean up.

According to MSDN, IAMFilterData::ParseFilterData is deprecated and
IFilterMapper2::EnumMatchingFilters should be used instead. This method
internally also calls FM2_ReadFilterData, but uses FM2_DeleteRegFilter to clean
up.

But there may be better ways to do this.