Function mbedtls_oid_get_extended_key_usage 

pub unsafe extern "C" fn mbedtls_oid_get_extended_key_usage(
    oid: *const mbedtls_asn1_buf,
    desc: *mut *const c_char,
) -> c_int

\brief Translate Extended Key Usage OID into description

\param oid OID to use \param desc place to store string pointer

\return 0 if successful, or MBEDTLS_ERR_OID_NOT_FOUND