Clean up network logging and code (#643)

* Apply clippy lints to beacon node

* Remove unnecessary logging and correct formatting

* Apply reviewers suggestions

beacon_node/eth2-libp2p/src/rpc/mod.rs

@@ -77,7 +77,7 @@ impl<TSubstream> RPC<TSubstream> {
         RPC {
             events: Vec::new(),
             marker: PhantomData,
-            log: log,
+            log,
         }
     }