Update callback_tracker.lua

Fixes #83

monarch/monarch.lua

@@ -879,7 +879,7 @@ function M.clear(cb)
 			local top = stack[#stack]
 			while top and top.visible do
 				stack[#stack] = nil
-				await(back_out, top, screen, WAIT_FOR_TRANSITION, resume)
+				await(back_out, top, stack[#stack - 1], WAIT_FOR_TRANSITION, resume)
 				top = stack[#stack]
 			end
 

monarch/utils/callback_tracker.lua

@@ -14,7 +14,7 @@ function M.create()
 
 	local function invoke_if_done()
 		if all_callbacks_done then
-			print("Warning: The same callback will be invoked twice from the callback tracker!", id or "")
+			print("Warning: The same callback will be invoked twice from the callback tracker!")
 		end
 		if callback_count == 0 and callback then
 			all_callbacks_done = true
@@ -52,6 +52,6 @@ end
 
 return setmetatable(M, {
 	__call = function(_, ...)
-		return M.create(...)
+		return M.create()
 	end
 })