worktree: drop get_worktrees() special-purpose sorting option

Of all the clients of get_worktrees(), only "git worktree list" wants
the list sorted in a very specific way; other clients simply don't care
about the order. Rather than imbuing get_worktrees() with special
knowledge about how various clients -- now and in the future -- may want
the list sorted, drop the sorting capability altogether and make it the
client's responsibility to sort the list if needed.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

worktree.h

@@ -18,17 +18,12 @@ struct worktree {
 	int lock_reason_valid; /* private */
 };
 
-/* Functions for acting on the information about worktrees. */
-
-#define GWT_SORT_LINKED (1 << 0) /* keeps linked worktrees sorted */
-
 /*
  * Get the worktrees.  The primary worktree will always be the first returned,
- * and linked worktrees will be pointed to by 'next' in each subsequent
- * worktree.  No specific ordering is done on the linked worktrees.
+ * and linked worktrees will follow in no particular order.
  *
  * The caller is responsible for freeing the memory from the returned
- * worktree(s).
+ * worktrees by calling free_worktrees().
  */
 struct worktree **get_worktrees(unsigned flags);