clippy fixes (#565)

frost-core/src/frost/identifier.rs

@@ -134,14 +134,7 @@ where
     C: Ciphersuite,
 {
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        let serialized_self = <<C::Group as Group>::Field>::little_endian_serialize(&self.0);
-        let serialized_other = <<C::Group as Group>::Field>::little_endian_serialize(&other.0);
-        // The default cmp uses lexicographic order; so we need the elements in big endian
-        serialized_self
-            .as_ref()
-            .iter()
-            .rev()
-            .partial_cmp(serialized_other.as_ref().iter().rev())
+        Some(self.cmp(other))
     }
 }
 

frost-core/src/tests/ciphersuite_generic.rs

@@ -405,7 +405,7 @@ where
                 .expect("should be nonzero");
             received_round1_packages
                 .entry(receiver_participant_identifier)
-                .or_insert_with(BTreeMap::new)
+                .or_default()
                 .insert(participant_identifier, round1_package.clone());
         }
     }