path-walk: drop redundant parse_tree() call

This call to parse_tree() was flagged by Coverity for ignoring the
return value. But if we look a little further up the function, we can
see that there is already a call to parse_tree_gently(), and we'll
return early if that fails. So by this point the tree will always be
parsed, and the call is redundant.

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

path-walk.c

@@ -126,7 +126,6 @@ static int add_tree_entries(struct path_walk_context *ctx,
 	strbuf_addstr(&path, base_path);
 	base_len = path.len;
 
-	parse_tree(tree);
 	init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
 	while (tree_entry(&desc, &entry)) {
 		struct type_and_oid_list *list;