tree-wide: fix needless borrows

found and fixed via clippy

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

pbs-datastore/src/snapshot_reader.rs

@@ -89,7 +89,7 @@ impl SnapshotReader {
 
     /// Returns an iterator for all used chunks.
     pub fn chunk_iterator(&self) -> Result<SnapshotChunkIterator, Error> {
-        SnapshotChunkIterator::new(&self)
+        SnapshotChunkIterator::new(self)
     }
 }