test: update test/parallel/test-fs-read.js

* Replace equal with strictEqual
* Update functions to arrow functions

PR-URL: https://github.com/nodejs/node/pull/8596
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/parallel/test-fs-read.js

@@ -11,12 +11,12 @@ fs.read(fd,
         expected.length,
         0,
         'utf-8',
-        common.mustCall(function(err, str, bytesRead) {
-          assert.ok(!err);
-          assert.equal(str, expected);
-          assert.equal(bytesRead, expected.length);
+        common.mustCall((err, str, bytesRead) => {
+          assert.ifError(err);
+          assert.strictEqual(str, expected);
+          assert.strictEqual(bytesRead, expected.length);
         }));
 
 var r = fs.readSync(fd, expected.length, 0, 'utf-8');
-assert.equal(r[0], expected);
-assert.equal(r[1], expected.length);
+assert.strictEqual(r[0], expected);
+assert.strictEqual(r[1], expected.length);