doc: change Node.js style to error-first style

We change the awkward "Node.js style callback" phrasing to the
more informative "error-first style callback," which is more
in line with its usage

Refs: nodejs#17593 (comment)

doc/api/errors.md

@@ -128,12 +128,12 @@ they are thrown *after* the calling code has already exited.
 Developers must refer to the documentation for each method to determine
 exactly how errors raised by those methods are propagated.
 
-### Node.js style callbacks
+### Error-first style callbacks
 
 <!--type=misc-->
 
 Most asynchronous methods exposed by the Node.js core API follow an idiomatic
-pattern  referred to as a "Node.js style callback". With this pattern, a
+pattern  referred to as an "error-first style callback". With this pattern, a
 callback function is passed to the method as an argument. When the operation
 either completes or an error is raised, the callback function is called with
 the Error object (if any) passed as the first argument. If no error was raised,
@@ -142,21 +142,21 @@ the first argument will be passed as `null`.
 ```js
 const fs = require('fs');
 
-function nodeStyleCallback(err, data) {
+function errorFirstStyleCallback(err, data) {
   if (err) {
     console.error('There was an error', err);
     return;
   }
   console.log(data);
 }
 
-fs.readFile('/some/file/that/does-not-exist', nodeStyleCallback);
-fs.readFile('/some/file/that/does-exist', nodeStyleCallback);
+fs.readFile('/some/file/that/does-not-exist', errorFirstStyleCallback);
+fs.readFile('/some/file/that/does-exist', errorFirstStyleCallback);
 ```
 
 The JavaScript `try / catch` mechanism **cannot** be used to intercept errors
 generated by asynchronous APIs.  A common mistake for beginners is to try to
-use `throw` inside a Node.js style callback:
+use `throw` inside an error-first style callback:
 
 ```js
 // THIS WILL NOT WORK:

doc/api/util.md

@@ -517,7 +517,7 @@ added: v8.0.0
 * `original` {Function}
 * Returns: {Function}
 
-Takes a function following the common Node.js callback style, i.e. taking a
+Takes a function following the common error-first style callback, i.e. taking a
 `(err, value) => ...` callback as the last argument, and returns a version
 that returns promises.
 
@@ -554,9 +554,9 @@ will return its value, see [Custom promisified functions][].
 
 `promisify()` assumes that `original` is a function taking a callback as its
 final argument in all cases. If `original` is not a function, `promisify()`
-will throw an error. If `original` is a function but its last argument is not a
-Node.js style callback, it will still be passed a Node.js style callback
-as its last argument.
+will throw an error. If `original` is a function but its last argument is not 
+an error-first style callback, it will still be passed an error-first style 
+callback as its last argument.
 
 ### Custom promisified functions