13438 Update prototypes to 2021

@@ -7,7 +7,7 @@
 .\" A full copy of the text of the CDDL should have accompanied this
 .\" 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>
 .\"