Silence some alerts due to overly verbose warnings. (#3946)

* statement-distribution: Only warn on relevant stuff.

* Silence warnings in availability-distribution.

* Demote more warnings.

* More consistency.

* info -> debug

polkadot/node/network/statement-distribution/src/lib.rs

@@ -1625,7 +1625,7 @@ impl StatementDistribution {
 					&requesting_peer,
 					&relay_parent,
 					&candidate_hash,
-				) {
+				)? {
 					return Err(NonFatal::RequestedUnannouncedCandidate(
 						requesting_peer,
 						candidate_hash,
@@ -1896,27 +1896,15 @@ fn requesting_peer_knows_about_candidate(
 	requesting_peer: &PeerId,
 	relay_parent: &Hash,
 	candidate_hash: &CandidateHash,
-) -> bool {
-	requesting_peer_knows_about_candidate_inner(
-		peers,
-		requesting_peer,
-		relay_parent,
-		candidate_hash,
-	)
-	.is_some()
-}
-
-/// Helper function for `requesting_peer_knows_about_statement`.
-fn requesting_peer_knows_about_candidate_inner(
-	peers: &HashMap<PeerId, PeerData>,
-	requesting_peer: &PeerId,
-	relay_parent: &Hash,
-	candidate_hash: &CandidateHash,
-) -> Option<()> {
-	let peer_data = peers.get(requesting_peer)?;
-	let knowledge = peer_data.view_knowledge.get(relay_parent)?;
-	knowledge.sent_candidates.get(&candidate_hash)?;
-	Some(())
+) -> NonFatalResult<bool> {
+	let peer_data = peers
+		.get(requesting_peer)
+		.ok_or_else(|| NonFatal::NoSuchPeer(*requesting_peer))?;
+	let knowledge = peer_data
+		.view_knowledge
+		.get(relay_parent)
+		.ok_or_else(|| NonFatal::NoSuchHead(*relay_parent))?;
+	Ok(knowledge.sent_candidates.get(&candidate_hash).is_some())
 }
 
 #[derive(Clone)]