ledger path reform: use Path/PathBuf instead of strings (#5344)

ledger-tool/tests/basic.rs

@@ -38,6 +38,8 @@ fn nominal() {
     let (ledger_path, _blockhash) = create_new_tmp_ledger!(&genesis_block);
     let ticks = ticks_per_slot as usize;
 
+    let ledger_path = ledger_path.to_str().unwrap();
+
     // Basic validation
     let output = run_ledger_tool(&["-l", &ledger_path, "verify"]);
     assert!(output.status.success());