char *ctl_mac_sprint_addr(char *dst, const CTL_NET_MAC_ADDR_t *addr, char sep);
ctl_mac_sprint_addr converts the address addr to hexadecimal notation, using sep to separate each octet, and writes the result to the object pointed to by dst. dst must be 18 characters or more for six hexadecimal octets, separators, and a terminating zero.
ctl_mac_sprint_addr returns dst.