Some small log improvements (#5110)

* improve provisioner log

* change log target from availability to availability-store

polkadot/node/core/av-store/src/lib.rs

@@ -50,7 +50,7 @@ pub use self::metrics::*;
 #[cfg(test)]
 mod tests;
 
-const LOG_TARGET: &str = "parachain::availability";
+const LOG_TARGET: &str = "parachain::availability-store";
 
 /// The following constants are used under normal conditions:
 

polkadot/node/core/provisioner/src/lib.rs

@@ -511,9 +511,10 @@ async fn select_candidates(
 
 	tracing::debug!(
 		target: LOG_TARGET,
-		"Selected {} candidates for {} cores",
-		candidates.len(),
-		availability_cores.len()
+		n_candidates = candidates.len(),
+		n_cores = availability_cores.len(),
+		?relay_parent,
+		"Selected candidates for cores",
 	);
 
 	Ok(candidates)