[c] Fix operator precedence: it should be unary minus instead equal

[Georgehu716]

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[imba-tjd]

csv was edited in #5286
I think it's ok to not fix it in this one.

[Georgehu716]

csv was edited in #5286 I think it's ok to not fix it in this one.

OK, nice.

[vendethiel]

Woops! Thanks