fix: upgrading to latest doxygen

base/mf_existvar.sas

@@ -11,7 +11,7 @@
   @param var (positional) - variable name
   @version 9.2
   @author Allan Bowe
-**/
+**/  /** @cond */
 
 %macro mf_existvar(libds /* 2 part dataset name */
       , var /* variable name */
@@ -29,4 +29,6 @@
       %let rc=%sysfunc(close(&dsid));
   %end;
 
-%mend;
+%mend;
+
+/** @endcond */