Fix SyntaxError introduced by a refactor in bc0f5ee

[blazczak]

Fixes the syntax error introduced by an incomplete refactor in bc0f5ee

$ brew update
==> Updating Homebrew...
To restore the stashed changes to /usr/local/Homebrew, run:
  cd /usr/local/Homebrew && git stash pop
  File "<string>", line 1
    import fcntl; fcntl.flock(, fcntl.LOCK_EX | fcntl.LOCK_NB)
                              ^
SyntaxError: invalid syntax

Caused by missed variable rename in bc0f5ee

The fix finishes the refactor by completing the variable rename and brings the code base back to a (more) consistent state.

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[ZhongRuoyu]

Thanks for catching and fixing this, @blazczak!

[MikeMcQuaid]

Whoops, thanks @blazczak!