win32: avoid warning in logging
win32: avoid warning in logging

markokr/libusual,rabbitt/libusual,ifduyue/libusual,rabbitt/libusual,markokr/libusual,rabbitt/libusual,rabbitt/libusual,ifduyue/libusual,markokr/libusual,ifduyue/libusual,mgjv/libusual,markokr/libusual,ifduyue/libusual,mgjv/libusual,mgjv/libusual,mgjv/libusual