fs: minor improvements to O_DSYNC

Refs: nodejs#15451

Author: tniessen

doc/api/fs.md

@@ -2806,12 +2806,13 @@ The following constants are meant for use with `fs.open()`.
   </tr>
   <tr>
     <td><code>O_SYNC</code></td>
-    <td>Flag indicating that the file is opened for synchronous I/O.</td>
+    <td>Flag indicating that the file is opened for synchronized I/O with write
+    operations waiting for file integrity.</td>
   </tr>
   <tr>
     <td><code>O_DSYNC</code></td>
-    <td>Flag indicating that the file is opened for synchronous I/O
-    with write operations waiting for data integrity.</td>
+    <td>Flag indicating that the file is opened for synchronized I/O with write
+    operations waiting for data integrity.</td>
   </tr>
   <tr>
     <td><code>O_SYMLINK</code></td>

test/parallel/test-fs-open-flags.js

@@ -81,10 +81,10 @@ common.expectsError(
   { code: 'ERR_INVALID_OPT_VALUE', type: TypeError }
 );
 
-if (common.isLinux === true) {
+if (common.isLinux) {
   const file = fixtures.path('a.js');
 
-  fs.open(file, O_DSYNC, common.mustCall(function(err, fd) {
+  fs.open(file, O_DSYNC, common.mustCall((err, fd) => {
     assert.ifError(err);
   }));
 }