clippy: use while let loops

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

src/api2/tape/restore.rs

@@ -343,10 +343,7 @@ fn restore_chunk_archive<'a>(
     let mut decoder = ChunkArchiveDecoder::new(reader);
 
     let result: Result<_, Error> = proxmox::try_block!({
-        loop {
+        while let Some((digest, blob)) = decoder.next_chunk()? {
-            match decoder.next_chunk()? {
-                Some((digest, blob)) => {
-
             if let Some(datastore) = datastore {
                 let chunk_exists = datastore.cond_touch_chunk(&digest, false)?;
                 if !chunk_exists {
@@ -367,9 +364,6 @@ fn restore_chunk_archive<'a>(
             }
             chunks.push(digest);
         }
-                None => break,
-            }
-        }
         Ok(())
     });
 

src/tools/parallel_handler.rs

@@ -134,11 +134,7 @@ impl<I: Send + 'static> ParallelHandler<I> {
         let mut msg_list = Vec::new();
 
         let mut i = 0;
-        loop {
+        while let Some(handle) = self.handles.pop() {
-            let handle = match self.handles.pop() {
-                Some(handle) => handle,
-                None => break,
-            };
             if let Err(panic) = handle.join() {
                 match panic.downcast::<&str>() {
                     Ok(panic_msg) => msg_list.push(