du: port to use the safe io functions

Author: sylvestre

src/uu/du/Cargo.toml

@@ -21,7 +21,13 @@ path = "src/du.rs"
 # For the --exclude & --exclude-from options
 glob = { workspace = true }
 clap = { workspace = true }
-uucore = { workspace = true, features = ["format", "fsext", "parser", "time"] }
+uucore = { workspace = true, features = [
+  "format",
+  "fsext",
+  "parser",
+  "time",
+  "safe-traversal",
+] }
 thiserror = { workspace = true }
 fluent = { workspace = true }