This PR backports upstream fix for CVE-2020-8037. This fix is only
relevant for tcpdump package, tcpdump-mini is not affeted by this issue.
Signed-off-by: Jan Pavlinec <jan.pavlinec@nic.cz>
[added missing commit description]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
