13438 Update prototypes to 2021

@@ -8,11 +8,11 @@
  * 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>
  */
 
 #ifndef _PROTOTYPE_H
 #define _PROTOTYPE_H