Revert "[node] force checkout vee-eight-lkgr"

This reverts commit 7fb1874d.

Reason for revert: Infra supports this now.

Original change's description:
> [node] force checkout vee-eight-lkgr
> 
> TBR=machenbach@chromium.org
> 
> Bug: chromium:860430
> Change-Id: I5554468a7c11038903fc3ab5eca067c230b2849a
> Reviewed-on: https://chromium-review.googlesource.com/1127370
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54279}

TBR=machenbach@chromium.org,yangguo@chromium.org

Change-Id: I5d99abb4885f8da9929ab826db47cd8ffc416b81
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:860430
Reviewed-on: https://chromium-review.googlesource.com/1127720Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54285}

tools/node/update_node.py

@@ -86,7 +86,6 @@ def ResetTarget(path):
   print ">> Resetting Node.js checkout"
   subprocess.check_call(["git", "reset", "--hard"], cwd=path)
   subprocess.check_call(["git", "clean", "-fxd"], cwd=path)
-  subprocess.check_call(["git", "checkout", "vee-eight-lkgr"], cwd=path)
 
 def UpdateTarget(repository, options, files_to_keep):
   source = os.path.join(options.v8_path, *repository)