a `defer` consumes more than one linear value

Why this fires¶

A defer, defer_ok or defer_err consumes more than one linear value. Each cleanup is armed by exactly one value, so an explicit consumption of that value can disarm it unambiguously.

defer close_both(a, b)   // TE177

Fix it¶

Split it into one defer per value:

defer a.close()
defer b.close()