fs: remove redundant callback check

PR-URL: #25160
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: ZYSzys

lib/fs.js

@@ -1570,7 +1570,7 @@ realpathSync.native = (path, options) => {
 
 
 function realpath(p, options, callback) {
-  callback = maybeCallback(typeof options === 'function' ? options : callback);
+  callback = typeof options === 'function' ? options : maybeCallback(callback);
   if (!options)
     options = emptyObj;
   else