fix clippy::map_clone: use .cloned() instead of .map(|x| x.clone())

Author: matthiaskrgr

src/librustc_codegen_ssa/back/write.rs

@@ -490,7 +490,7 @@ fn copy_all_cgu_workproducts_to_incr_comp_cache_dir(
     let _timer = sess.timer("copy_all_cgu_workproducts_to_incr_comp_cache_dir");
 
     for module in compiled_modules.modules.iter().filter(|m| m.kind == ModuleKind::Regular) {
-        let path = module.object.as_ref().map(|path| path.clone());
+        let path = module.object.as_ref().cloned();
 
         if let Some((id, product)) =
             copy_cgu_workproduct_to_incr_comp_cache_dir(sess, &module.name, &path)