Merge branch 'jk/unused-annotation'

Annotate function parameters that are not used (but cannot be
removed for structural reasons), to prepare us to later compile
with -Wunused warning turned on.

* jk/unused-annotation:
  is_path_owned_by_current_uid(): mark "report" parameter as unused
  run-command: mark unused async callback parameters
  mark unused read_tree_recursive() callback parameters
  hashmap: mark unused callback parameters
  config: mark unused callback parameters
  streaming: mark unused virtual method parameters
  transport: mark bundle transport_options as unused
  refs: mark unused virtual method parameters
  refs: mark unused reflog callback parameters
  refs: mark unused each_ref_fn parameters
  git-compat-util: add UNUSED macro

environment.c

@@ -334,10 +334,10 @@ static void set_git_dir_1(const char *path)
 	setup_git_env(path);
 }
 
-static void update_relative_gitdir(const char *name,
+static void update_relative_gitdir(const char *UNUSED(name),
 				   const char *old_cwd,
 				   const char *new_cwd,
-				   void *data)
+				   void *UNUSED(data))
 {
 	char *path = reparent_relative_path(old_cwd, new_cwd, get_git_dir());
 	struct tmp_objdir *tmp_objdir = tmp_objdir_unapply_primary_odb();