Fix warning C4365 emitted from printf.h

[Baardi]

Compiler: MSVC, Windows x64, Visual Studio 17.9.1
C++ standard: /std::c++latest
Fmtlib version: 10.2.1

Hi. Thanks for a fantastic library.

While we've generally gotten a few warnings from fmtlib during the last few years, they have decreased over time. On the 10.2.1 release, with our current setup, we only got a single one, a C4365. There might be others, that aren't caught by us, since we disable a few warnings. Our warning level is /W4.

I have not yet been able to create a minimal reproduction case. The following code will compile in a freshly created Visual Studio project, but not in ours:

#define FMT_HEADER_ONLY
#include "fmt/printf.h"

void test
{
   fmt::printf("%s", "test");
}

But the fix for this issue, worked for us. If required I can work more on finding a minimal reproduction case.

[vitaut]

thanks