src: mqtt: Replace single-branch match with if let

src/mqtt.rs

@@ -70,13 +70,10 @@ impl MQTT {
             let notification = self.eventloop.poll().await?;
             debug!("Notification = {:?}", notification);
 
-            match notification {
+            if let Event::Incoming(Incoming::Publish(p)) = notification {
-                Event::Incoming(Incoming::Publish(p)) => {
                 let msg: StatusMessage = serde_json::from_slice(p.payload.as_ref())?;
                 info!("Message: {:?}", msg);
                 callback(msg);
-                },
-                _ => (),
             }
         }