Remove unnecessary fixups

[malthe]

Some refactoring after changes in #434.

The specific lineno is not important here and because mypy wants an integer (and not None or simply omitting the parameter), we'll just provide an arbitrary value, e.g. -1.

The requirement of having a lineno is used some places in the Python standard library's AST module, concerned with type hints.

[coveralls]

Pull Request Test Coverage Report for Build 12455819633

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.009%) to 92.331%

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Totals
Change from base Build 12454306269:	-0.009%
Covered Lines:	3915
Relevant Lines:	4166

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💛 - Coveralls