For Win32, don't cast ssize_t while printing

Bug: http://b/69933068

This is a partial revert of
https://android-review.googlesource.com/c/platform/frameworks/base/+/109433
so we can use Clang for windows cross compilation.

Clang does not allow a cast to 'signed size_t' and both Clang and
current MinGW accept a ssize_t to the '%zd' format specifier.

Test: m native-host, m native-host-cross with both MinGW and Clang
Change-Id: I5366622b91be1433f6c533c55a9ae429b57c7a27