Removal of POOL_DIAGNOSTIC

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

Hi,

Unless anyone objects, I will remove POOL_DIAGNOSTIC.  Since default
allocator is pool_cache(9), in post-netbsd-5 it is not really useful
nor really used (note that after kmem(9) changes it does not compile).
For pool_cache(9), existing consistency checks and safeguards under
DEBUG/DIAGNOSTIC are fairly effective.

http://www.netbsd.org/~rmind/pool_diag.diff

-- 
Mindaugas