Remove a leftover unused struct.

tmux.h

@@ -735,28 +735,6 @@ struct window_mode {
 };
 #define WINDOW_MODE_TIMEOUT 180
 
-/* Structures for choose mode. */
-struct window_choose_data {
-	struct client		*start_client;
-	struct session		*start_session;
-
-	u_int			 idx;
-	int			 type;
-#define TREE_OTHER 0x0
-#define TREE_WINDOW 0x1
-#define TREE_SESSION 0x2
-
-	struct session		*tree_session; /* session of items in tree */
-
-	struct winlink		*wl;
-	int			 pane_id;
-
-	char			*ft_template;
-	struct format_tree	*ft;
-
-	char			*command;
-};
-
 /* Child window structure. */
 struct window_pane {
 	u_int		 id;