fs: refactor deprecated functions for readability

This is a small refactor to make an object more readable (IMO).

Yeah, I spent a bit longer looking at the code and misunderstanding it
than I care to admit right now.

PR-URL: #12910
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/fs.js

@@ -2140,10 +2140,8 @@ WriteStream.prototype.destroySoon = WriteStream.prototype.end;
 var SyncWriteStream = internalFS.SyncWriteStream;
 Object.defineProperty(fs, 'SyncWriteStream', {
   configurable: true,
-  get: internalUtil.deprecate(() => {
-    return SyncWriteStream;
-  }, 'fs.SyncWriteStream is deprecated.', 'DEP0061'),
-  set: internalUtil.deprecate((val) => {
-    SyncWriteStream = val;
-  }, 'fs.SyncWriteStream is deprecated.', 'DEP0061')
+  get: internalUtil.deprecate(() => SyncWriteStream,
+                              'fs.SyncWriteStream is deprecated.', 'DEP0061'),
+  set: internalUtil.deprecate((val) => { SyncWriteStream = val; },
+                              'fs.SyncWriteStream is deprecated.', 'DEP0061')
 });