Apply suggestions from code review

Co-authored-by: Mestery <[email protected]>

Author: benjamingr

doc/api/stream.md

@@ -2140,7 +2140,7 @@ added: v17.4.0
     aborted.
 * Returns: {Promise} a promise for the final value of the reduction.
 
-This method calls `fn`  on each chunk of the stream in order passing it the
+This method calls `fn` on each chunk of the stream in order passing it the
 result from the calculation on the previous element. It returns a promise for
 the final value of the reduction.
 
@@ -2150,7 +2150,6 @@ initial value. If the stream is empty, the promise is rejected with a
 
 ```mjs
 import { Readable } from 'stream';
-import { createReadStream } from 'fs';
 
 const ten = await Readable.from([1, 2, 3, 4]).reduce((previous, data) => {
   return previous + data;

test/parallel/test-stream-reduce.js

@@ -105,5 +105,5 @@ function sum(p, c) {
 {
   // Test result is a Promise
   const result = Readable.from([1, 2, 3, 4, 5]).reduce(sum, 0);
-  assert.strictEqual(result instanceof Promise, true);
+  assert.ok(result instanceof Promise);
 }