fix warnings

miner/src/memory_pool.rs

@@ -15,7 +15,6 @@ use std::collections::HashSet;
 use std::collections::BTreeSet;
 use ser::{Serializable, serialize};
 use heapsize::HeapSizeOf;
-use db::TransactionMetaProvider;
 
 /// Transactions ordering strategy
 #[cfg_attr(feature="cargo-clippy", allow(enum_variant_names))]
@@ -713,7 +712,7 @@ impl PreviousTransactionOutputProvider for MemoryPool {
 			.cloned()
 	}
 
-	fn is_spent(&self, prevout: &OutPoint) -> bool {
+	fn is_spent(&self, _prevout: &OutPoint) -> bool {
 		false
 	}
 }

sync/src/synchronization_verifier.rs

@@ -206,7 +206,7 @@ impl PreviousTransactionOutputProvider for EmptyTransactionOutputProvider {
 		None
 	}
 
-	fn is_spent(&self, prevout: &OutPoint) -> bool {
+	fn is_spent(&self, _prevout: &OutPoint) -> bool {
 		false
 	}
 }