Test fail on s390x

[cathay4t]

---- nla::tests::network_byteorder stdout ----
thread 'nla::tests::network_byteorder' panicked at 'range end index 2048 out of range for slice of length 8', src/nla.rs:168:10
note: run with RUST_BACKTRACE=1 environment variable to display a backtrace
failures:
nla::tests::network_byteorder
test result: FAILED. 2 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
error: test failed, to rerun pass --lib

[glaubitz]

It does not just fail on s390x, but on all big-endian targets.

See: https://buildd.debian.org/status/package.php?p=rust-netlink-packet-utils&suite=sid

[glaubitz]

Access to big-endian machines can be obtained through the GCC Compile Farm.

See: https://gcc.gnu.org/wiki/CompileFarm

[siretart]

The failing test in question was introduced in 2b7a291

What's the #70 it is referring to? -- I guess this code was moved here from somewhere else on github?

[siretart]

@hermantolim PTAL