mesa|mapi: replace _mesa_[v]snprintf with [v]snprintf

mesa|mapi: replace _mesa_[v]snprintf with [v]snprintf

MSVC 2015 and newer has perfectly valid snprintf and vsnprintf
implementations, let's just use those.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3024>