Fix -wformat warnings on Windows

[jeroen]

CRAN started enfocring -wformat on Windows, which revealed some printf bugs in mongo-c-driver.
See: https://www.r-project.org/nosvn/R.check/r-devel-windows-x86_64/mongolite-00check.html

@kevinAlbs

[kevinAlbs]

Thank you for the heads up @jeroen. Filed https://jira.mongodb.org/browse/CDRIVER-4484

[jeroen]

Can you also have a look at these -Wstrict-prototype warnings (i.e. missing void for functions without parameters)? These are going be problematic for C23: https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-fedora-clang/mongolite-00check.html

[kevinAlbs]

@jeroen is this blocking mongolite from being released on CRAN? That may help us determine how to schedule.

[jeroen]

We do need to fix these warnings if we want to push out a new release, But it's not super urgent because we don't have to do a mongolite release soon, there are no urgent problems afaik.

[eramongodb]

@jeroen Fixes have been merged in mongodb/mongo-c-driver#1120. Please let us know if this commit resolved the issues reported.

[jeroen]

Thanks! That looks good.