Fix clippy lint warnings

Change-Id: I6bfbbb2a9f164105dcedd2c2ac53093211c35137
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/qg/+/126918
Reviewed-by: Erik Gilling <konkers@google.com>
Pigweed-Auto-Submit: Alexei Frolov <frolv@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/qg/src/project/mod.rs b/qg/src/project/mod.rs
index 0c4c8e2..fb243e8 100644
--- a/qg/src/project/mod.rs
+++ b/qg/src/project/mod.rs
@@ -318,10 +318,10 @@
 
         let target = project.registry().get_target("dep-test:a").unwrap();
 
-        let _ = project.target_output_directory(&target).unwrap();
+        project.target_output_directory(&target).unwrap();
         assert!(test_project.relative_path("qg/out/dep-test/a").exists());
 
-        let _ = project.target_work_directory(&target).unwrap();
+        project.target_work_directory(&target).unwrap();
         assert!(test_project.relative_path("qg/work/dep-test/a").exists());
     }
 
diff --git a/qg/src/util.rs b/qg/src/util.rs
index 6bd1320..1bd6444 100644
--- a/qg/src/util.rs
+++ b/qg/src/util.rs
@@ -54,9 +54,9 @@
 
         let src_relative_path = entry
             .path()
-            .strip_prefix(&src)
+            .strip_prefix(src)
             .expect("child entry should be in directory path");
-        let dest_location = dest.join(&src_relative_path);
+        let dest_location = dest.join(src_relative_path);
 
         if entry.file_type().is_dir() {
             std::fs::create_dir_all(dest_location)?;