3192-dyno update plugin example

fixed function `log_active_rules` parameter

Author: GitNiko

text/3192-dyno.md

@@ -266,7 +266,7 @@ fn log_plugin_stats(plugin: &dyn Plugin) {
     }
 }
 
-fn log_active_rules(f: &mut dyn Plugin) {
+fn log_active_rules(plugin: &mut dyn Plugin) {
     if let Some(rules) = plugin.borrow_plugin_data::<[Rule]>() {
         for r in rules {
             log(plugin.id(), r);