PIV-47: Restored BN_bn2bin_fixed, it is not the same as BN_bn2binpad
PIV-47: Restored BN_bn2bin_fixed, it is not the same as BN_bn2binpad

Yubico/yubico-piv-tool,Yubico/yubico-piv-tool,Yubico/yubico-piv-tool