bug#74385: [PATCH 1/4] srfi-64: Fix maybe-print-prop.

Tomas Volf <[email protected]> skribis:

> Previously it always printed the property, regardless of whether it was set or
> not.
>
> * module/srfi/srfi-64.scm (test-on-test-end-simple)[maybe-print-prop]:
> Print only set properties.

[...]

> This will help to properly debug failing tests like:
>
>     (test-equal "some failing test" "a b " "a b")
>
> Before there was no way to tell that one "a b" as extra trailing space, now
> there is.
>
> * module/srfi/srfi-64.scm (test-on-test-end-simple)['expected-value]
> ['expected-error, 'actual-value, 'actual-error]: Print using ~s.
> [maybe-print-prop]: Take the code for format as a parameter.

These two LGTM.  Thanks!