Fix argument order in Tracer::new callbacks.

examples/loopback.rs

@@ -77,7 +77,7 @@ fn main() {
     }
 
     let mut device = Loopback::new();
-    let mut device = EthernetTracer::new(device, |printer, _timestamp| trace!("{}", printer));
+    let mut device = EthernetTracer::new(device, |_timestamp, printer| trace!("{}", printer));
 
     let mut arp_cache_entries: [_; 8] = Default::default();
     let mut arp_cache = SliceArpCache::new(&mut arp_cache_entries[..]);

examples/utils.rs

@@ -78,7 +78,7 @@ pub fn setup_device(more_args: &[&str])
     let seed = SystemTime::now().duration_since(UNIX_EPOCH).unwrap().subsec_nanos();
 
     let device = TapInterface::new(&matches.free[0]).unwrap();
-    let device = EthernetTracer::new(device, |printer, _timestamp| trace!("{}", printer));
+    let device = EthernetTracer::new(device, |_timestamp, printer| trace!("{}", printer));
     let mut device = FaultInjector::new(device, seed);
     device.set_drop_chance(drop_chance);
     device.set_corrupt_chance(corrupt_chance);