More stats to SIOCIPFCFWCFG and add SIOCIPFCFWNEWSZ to affect ring-buffer size.

*** 25,39 ****
  # Copyright 2019 Joyent, Inc.
  #
  
  cfw_evdrops
  cfw_evreports
! cfw_evring
  cfw_ringcv
  cfw_ringend
  cfw_ringfull
  cfw_ringlock
  cfw_ringstart
  cfw_timeout_tries
  cfw_timeout_wait
  hook4_vnd_in
  hook4_vnd_out
--- 25,41 ----
  # Copyright 2019 Joyent, Inc.
  #
  
  cfw_evdrops
  cfw_evreports
! cfw_ring
  cfw_ringcv
  cfw_ringend
  cfw_ringfull
  cfw_ringlock
+ cfw_ringmask
+ cfw_ringsize
  cfw_ringstart
  cfw_timeout_tries
  cfw_timeout_wait
  hook4_vnd_in
  hook4_vnd_out