coap_tinydtls.c: Fix ASN1 when calling validate_cn_call_back
coap_tinydtls.c: Fix ASN1 when calling validate_cn_call_back

Remove the initial size of the ASN1 information and tidy up some #define.

authmillenon/libcoap,authmillenon/libcoap,authmillenon/libcoap