CLEANUP: pools: get rid of CONFIG_HAP_POOLS

CLEANUP: pools: get rid of CONFIG_HAP_POOLS

This one was set in defaults.h only when neither DEBUG_NO_POOLS nor
DEBUG_UAF were set. This was not the most convenient location to look
for it, and it was only used in pool.c to decide on the initial value
of POOL_DBG_NO_CACHE.

Let's just use DEBUG_NO_POOLS || DEBUG_UAF directly on this flag and
get rid of the intermediary condition. This also has the benefit of
removing a double inversion, which is always nice for understanding.