LRU Refactor.

Simplify underlying LRU model, esp. locking.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Dont leak qlane lock in dec_pin_ref.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Safely unref entries on no queue.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Hash only (256) packet bytes in drc_tcp_hash, not the bytes plus
the redundant handle data.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>