Fix pcap link header size
Fix pcap link header size

The header is not always ethernet, we now check for the correct link
type to get the byte count to skip.

nabilbendafi/haka,Wingless-Archangel/haka,LubyRuffy/haka,lcheylus/haka,lcheylus/haka,nabilbendafi/haka,Wingless-Archangel/haka,LubyRuffy/haka,lcheylus/haka,haka-security/haka,haka-security/haka,haka-security/haka,nabilbendafi/haka