pcap_datalink_ex() in linktypes.html

[Denis Ovsienko]

Hello all.

Whilst updating some markup in linktypes.html, I wanted to change the
reference to pcap_datalink_ex() into a hyperlink to respective man page,
but it turned out there is no such function in libpcap in the first
place. There is pcap_datalink_ext(), which has been around since 2007,
but is not mentioned in any of libpcap man pages. Clearly that means at
least one loose end, but after a brief look I could not tell exactly
how to address that.

-- 
    Denis Ovsienko