Update for clippy 1.50 (#2193)

## Issue Addressed

NA

## Proposed Changes

Rust 1.50 has landed 🎉

The shiny new `clippy` peers down upon us mere mortals with disgust. Brutish peasants wrapping our `usize`s in superfluous `Option`s... tsk tsk.

I've performed the goat sacrifice and corrected our evil ways in this PR. Tonight we shall pray that Github Actions bestows the almighty green tick upon us.

## Additional Info

NA


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>

beacon_node/eth2_libp2p/src/behaviour/mod.rs

@@ -893,7 +893,7 @@ impl<TSpec: EthSpec> Behaviour<TSpec> {
         }
 
         // perform gossipsub score updates when necessary
-        while let Poll::Ready(_) = self.update_gossipsub_scores.poll_tick(cx) {
+        while self.update_gossipsub_scores.poll_tick(cx).is_ready() {
             self.peer_manager.update_gossipsub_scores(&self.gossipsub);
         }
 

beacon_node/eth2_libp2p/src/discovery/enr_ext.rs

@@ -29,7 +29,7 @@ pub trait EnrExt {
 /// Extend ENR CombinedPublicKey for libp2p types.
 pub trait CombinedKeyPublicExt {
     /// Converts the publickey into a peer id, without consuming the key.
-    fn into_peer_id(&self) -> PeerId;
+    fn as_peer_id(&self) -> PeerId;
 }
 
 /// Extend ENR CombinedKey for conversion to libp2p keys.
@@ -41,7 +41,7 @@ pub trait CombinedKeyExt {
 impl EnrExt for Enr {
     /// The libp2p `PeerId` for the record.
     fn peer_id(&self) -> PeerId {
-        self.public_key().into_peer_id()
+        self.public_key().as_peer_id()
     }
 
     /// Returns a list of multiaddrs if the ENR has an `ip` and either a `tcp` or `udp` key **or** an `ip6` and either a `tcp6` or `udp6`.
@@ -195,7 +195,7 @@ impl CombinedKeyPublicExt for CombinedPublicKey {
     /// Converts the publickey into a peer id, without consuming the key.
     ///
     /// This is only available with the `libp2p` feature flag.
-    fn into_peer_id(&self) -> PeerId {
+    fn as_peer_id(&self) -> PeerId {
         match self {
             Self::Secp256k1(pk) => {
                 let pk_bytes = pk.to_bytes();

beacon_node/eth2_libp2p/src/peer_manager/mod.rs

@@ -972,7 +972,7 @@ impl<TSpec: EthSpec> Stream for PeerManager<TSpec> {
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         // perform the heartbeat when necessary
-        while let Poll::Ready(_) = self.heartbeat.poll_tick(cx) {
+        while self.heartbeat.poll_tick(cx).is_ready() {
             self.heartbeat();
         }
 

beacon_node/eth2_libp2p/src/rpc/rate_limiter.rs

@@ -240,7 +240,7 @@ impl Future for RPCRateLimiter {
     type Output = ();
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
-        while let Poll::Ready(_) = self.prune_interval.poll_tick(cx) {
+        while self.prune_interval.poll_tick(cx).is_ready() {
             self.prune();
         }