Update examples/listen_uevents.rs

[manio]

Slice was wrong leading to from_netlink_packet() panicking.

[lu-zero]

How exactly is it wrong?

[manio]

Like this:

thread 'tokio-runtime-worker' panicked at src/main.rs:135:60:
called `Result::unwrap()` on an `Err` value: action not found
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

line 135 is:

            let u = UEvent::from_netlink_packet(&buf[..n]).unwrap();

from your example.
I am running it on arm-unknown-linux-gnueabihf

[lu-zero]

Sigh the example could be cleaned up further.

[lu-zero]

Thank you for providing a fix