repl: remove obsolete completer variable

It is also assigned in readline. There is not need to assign the
variable twice.

Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>

PR-URL: #33294
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/repl.js

@@ -647,10 +647,6 @@ function REPLServer(prompt,
     enumerable: true
   });
 
-  // Figure out which "complete" function to use.
-  self.completer = (typeof options.completer === 'function') ?
-    options.completer : completer;
-
   function completer(text, cb) {
     complete.call(self, text, self.editorMode ?
       self.completeOnEditorMode(cb) : cb);
@@ -659,7 +655,7 @@ function REPLServer(prompt,
   Interface.call(this, {
     input: options.input,
     output: options.output,
-    completer: self.completer,
+    completer: options.completer || completer,
     terminal: options.terminal,
     historySize: options.historySize,
     prompt