fix clippy warnings (#439)

fix clippy

p2p/address-book/src/store.rs

@@ -46,10 +46,7 @@ pub(crate) fn save_peers_to_disk<Z: BorshNetworkZone>(
 
     spawn_blocking(move || {
         fs::create_dir_all(dir)?;
-        match fs::write(&tmp_file, &data) {
-            Ok(_) => fs::rename(tmp_file, file),
-            Err(x) => Err(x),
-        }
+        fs::write(&tmp_file, &data).and_then(|()| fs::rename(tmp_file, file))
     })
 }