13438 Update prototypes to 2021

@@ -15,7 +15,7 @@
  * 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>
  */