simplify RefInfo fmt (#7929)

util/journaldb/src/earlymergedb.rs

@@ -16,7 +16,6 @@
 
 //! Disk-backed `HashDB` implementation.
 
-use std::fmt;
 use std::collections::HashMap;
 use std::collections::hash_map::Entry;
 use std::sync::Arc;
@@ -32,7 +31,7 @@ use ethereum_types::H256;
 use error::{BaseDataError, UtilError};
 use bytes::Bytes;
 
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 struct RefInfo {
 	queue_refs: usize,
 	in_archive: bool,
@@ -42,18 +41,6 @@ impl HeapSizeOf for RefInfo {
 	fn heap_size_of_children(&self) -> usize { 0 }
 }
 
-impl fmt::Display for RefInfo {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		write!(f, "{}+{}", self.queue_refs, if self.in_archive {1} else {0})
-	}
-}
-
-impl fmt::Debug for RefInfo {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		write!(f, "{}+{}", self.queue_refs, if self.in_archive {1} else {0})
-	}
-}
-
 #[derive(Clone, PartialEq, Eq)]
 enum RemoveFrom {
 	Queue,