Segv in dns_mode_parse test

[tomaszjonak]

Build in docker container fails. Prolly related to unsafe stuff in pcap iterator.

==8962== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==8962==  Access not within mapped region at address 0x0
==8962==    at 0x403546: nom::nom::be_u16 (nom.rs:346)
==8962==    by 0x56995A: kprobe::protocol::dns::parser::header (<::nom::macros::named macros>:13)
==8962==    by 0x566129: kprobe::protocol::dns::parser::message (macros.rs:28)
==8962==    by 0x56581D: kprobe::protocol::dns::parser::parse_message (parser.rs:72)
==8962==    by 0x4EAB41: kprobe::mode::dns::Dns::parse (dns.rs:79)
==8962==    by 0x48150E: kprobe::tests::modes::dns_mode_parse (modes.rs:15)
==8962==    by 0x430FB9: kprobe::tests::modes::dns_mode_parse::{{closure}} (modes.rs:6)
==8962==    by 0x416F4D: core::ops::function::FnOnce::call_once (function.rs:227)
==8962==    by 0x9AB9DE: <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once (boxed.rs:922)
==8962==    by 0x1626B19: __rust_maybe_catch_panic (lib.rs:80)
==8962==    by 0x9C61ED: try<(),std::panic::AssertUnwindSafe<alloc::boxed::Box<FnOnce<()>>>> (panicking.rs:271)
==8962==    by 0x9C61ED: catch_unwind<std::panic::AssertUnwindSafe<alloc::boxed::Box<FnOnce<()>>>,()> (panic.rs:394)
==8962==    by 0x9C61ED: test::run_test::run_test_inner::{{closure}} (lib.rs:1413)
==8962==    by 0x9A1254: std::sys_common::backtrace::__rust_begin_short_backtrace (backtrace.rs:126)