tree wide: some stylistic clippy fixes

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

src/bin/proxmox_backup_debug/api.rs

@@ -453,7 +453,8 @@ async fn ls(
         .noheader(true)
         .sortby("name", false);
 
-    let res = get_api_children(path.unwrap_or(String::from("/")), rpcenv).await?;
+    let path = path.unwrap_or_else(|| "".into());
+    let res = get_api_children(path, rpcenv).await?;
 
     format_and_print_result_full(
         &mut serde_json::to_value(res)?,

src/bin/proxmox_backup_debug/inspect.rs

@@ -119,7 +119,7 @@ fn inspect_chunk(
     let chunk_path = Path::new(&chunk);
 
     if digest.is_none() && use_filename_as_digest {
-        digest = Some(if let Some((_, filename)) = chunk.rsplit_once("/") {
+        digest = Some(if let Some((_, filename)) = chunk.rsplit_once('/') {
             String::from(filename)
         } else {
             chunk.clone()