13438 Update prototypes to 2021

@@ -10,8 +10,8 @@
 # source.  A copy of the CDDL is also available via the Internet at
 # http://www.illumos.org/license/CDDL.
 #
 
 #
-# Copyright 2020 <contributor>
+# Copyright 2021 <contributor>
 #