Avoid asprintf.
Avoid asprintf.

To improve portability, we do malloc() + snprintf() instead.

madrat-/yubico-pam,eworm-de/yubico-pam,Yubico/yubico-pam,Yubico/yubico-pam,eworm-de/yubico-pam,madrat-/yubico-pam,Yubico/yubico-pam,eworm-de/yubico-pam,madrat-/yubico-pam