12167 Update prototypes to 2020

*** 10,17 ****
  # source.  A copy of the CDDL is also available via the Internet at
  # http://www.illumos.org/license/CDDL.
  #
  
  #
! # Copyright 2019 <contributor>
  #
  
--- 10,17 ----
  # source.  A copy of the CDDL is also available via the Internet at
  # http://www.illumos.org/license/CDDL.
  #
  
  #
! # Copyright 2020 <contributor>
  #