mark unused read_tree_recursive() callback parameters

We pass a callback to read_tree_recursive(), but not every callback
needs every parameter. Let's mark the unused ones to satisfy
-Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

archive-tar.c

@@ -421,7 +421,7 @@ static int git_tar_config(const char *var, const char *value, void *cb)
 	return tar_filter_config(var, value, cb);
 }
 
-static int write_tar_archive(const struct archiver *ar,
+static int write_tar_archive(const struct archiver *UNUSED(ar),
 			     struct archiver_args *args)
 {
 	int err = 0;

archive-zip.c

@@ -618,7 +618,7 @@ static int archive_zip_config(const char *var, const char *value,
 	return userdiff_config(var, value);
 }
 
-static int write_zip_archive(const struct archiver *ar,
+static int write_zip_archive(const struct archiver *UNUSED(ar),
 			     struct archiver_args *args)
 {
 	int err;

archive.c

@@ -382,7 +382,8 @@ struct path_exists_context {
 	struct archiver_args *args;
 };
 
-static int reject_entry(const struct object_id *oid, struct strbuf *base,
+static int reject_entry(const struct object_id *UNUSED(oid),
+			struct strbuf *base,
 			const char *filename, unsigned mode,
 			void *context)
 {

builtin/checkout.c

@@ -125,7 +125,7 @@ static int post_checkout_hook(struct commit *old_commit, struct commit *new_comm
 }
 
 static int update_some(const struct object_id *oid, struct strbuf *base,
-		const char *pathname, unsigned mode, void *context)
+		       const char *pathname, unsigned mode, void *UNUSED(context))
 {
 	int len;
 	struct cache_entry *ce;

builtin/log.c

@@ -645,9 +645,10 @@ static int show_tag_object(const struct object_id *oid, struct rev_info *rev)
 	return 0;
 }
 
-static int show_tree_object(const struct object_id *oid,
-		struct strbuf *base,
-		const char *pathname, unsigned mode, void *context)
+static int show_tree_object(const struct object_id *UNUSED(oid),
+			    struct strbuf *UNUSED(base),
+			    const char *pathname, unsigned mode,
+			    void *context)
 {
 	FILE *file = context;
 	fprintf(file, "%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");

builtin/ls-tree.c

@@ -142,7 +142,7 @@ static int show_recursive(const char *base, size_t baselen, const char *pathname
 }
 
 static int show_tree_fmt(const struct object_id *oid, struct strbuf *base,
-			 const char *pathname, unsigned mode, void *context)
+			 const char *pathname, unsigned mode, void *UNUSED(context))
 {
 	size_t baselen;
 	int recurse = 0;
@@ -213,7 +213,7 @@ static void show_tree_common_default_long(struct strbuf *base,
 
 static int show_tree_default(const struct object_id *oid, struct strbuf *base,
 			     const char *pathname, unsigned mode,
-			     void *context)
+			     void *UNUSED(context))
 {
 	int early;
 	int recurse;
@@ -230,7 +230,8 @@ static int show_tree_default(const struct object_id *oid, struct strbuf *base,
 }
 
 static int show_tree_long(const struct object_id *oid, struct strbuf *base,
-			  const char *pathname, unsigned mode, void *context)
+			  const char *pathname, unsigned mode,
+			  void *UNUSED(context))
 {
 	int early;
 	int recurse;
@@ -259,7 +260,8 @@ static int show_tree_long(const struct object_id *oid, struct strbuf *base,
 }
 
 static int show_tree_name_only(const struct object_id *oid, struct strbuf *base,
-			       const char *pathname, unsigned mode, void *context)
+			       const char *pathname, unsigned mode,
+			       void *UNUSED(context))
 {
 	int early;
 	int recurse;
@@ -279,7 +281,8 @@ static int show_tree_name_only(const struct object_id *oid, struct strbuf *base,
 }
 
 static int show_tree_object(const struct object_id *oid, struct strbuf *base,
-			    const char *pathname, unsigned mode, void *context)
+			    const char *pathname, unsigned mode,
+			    void *UNUSED(context))
 {
 	int early;
 	int recurse;

merge-recursive.c

@@ -456,7 +456,7 @@ static void unpack_trees_finish(struct merge_options *opt)
 	clear_unpack_trees_porcelain(&opt->priv->unpack_opts);
 }
 
-static int save_files_dirs(const struct object_id *oid,
+static int save_files_dirs(const struct object_id *UNUSED(oid),
 			   struct strbuf *base, const char *path,
 			   unsigned int mode, void *context)
 {