Use gnu_printf format with MinGW
Use gnu_printf format with MinGW

We don't actually *need* any of the GNU printf format specifiers.

However, older versions of MinGW will complain about C99-compliant
specifiers like %lld unless 'gnu_printf' is used.

Signed-off-by: Paul Cercueil <a027184a55211cd23e3f3094f1fdc728df5e0500@crapouillou.net>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio