Bug in the error handling in TTMs pool implementation

[Christian König]

Hi guys,

some users ran into an OOM situation and discovered another problem in 
the error handling in TTMs page pool implementation.

@Karolina do you of hand know a way how we could exercise this in a TTM 
unit test? Basically we would need to redirect the alloc_pages_node() 
symbol to an unit test internal function and let it return an error (or 
something like that).

@Thomas you recently discovered and fixed bugs in that. I've just gone 
over the code once more, but can't find anything. Any idea what might be 
wrong?

Regards,
Christian.