Don't crash on failing DRIVER_FindFromHDrvr

[Eric Pouech]

> Strange: we don't see the RtlHeapAllocate function. But then I remember that
> the application (_impact.exe from the Xilinx ISE suite) uses the shsmp library
> for memory allocation (http://www.microquill.com/smartheap/sh_tspec.htm).
> 
> So our HeapAlloc get patched by the Microquill code, but probably
> HeapValidate dose not get patched and things diverge. 
> 
> Eric, can we do the memory validation perhaps in some other way then by
> HeapValidate ?
several questions here:
- if your theory (about missing HeapValidate func) is right: then I 
think that this memory manager is rather broken and should be fixed and 
not Wine
- but on the other hand, how could you explain that it did work at some 
point (ie didn't crash) and did it afterwards ? This doesn't seem too 
logical to me. Perhaps the smartheap API interception mechanism isn't 
that stable on Wine.
IMO, you should start looking at the interception code and see if it 
puts something in place for HeapValidate, then we'll see what we could 
do (one quickie is to use RtlValidateHeap instead of HeapValidate, but 
that's *really* ugly).
A+