[u_inv] Move part of item_name's globalstep into a step function

- For #179

mods/unified_inventory/item_names.lua

@@ -2,7 +2,6 @@
 
 local wield = {}
 local huds = {}
-local dtimes = {}
 local dlimit = 3  -- HUD element will be hidden after this many seconds
 local air_hud_mod = minetest.get_modpath("4air")
 local hud_mod = minetest.get_modpath("hud")
@@ -25,23 +24,24 @@ end
 
 minetest.register_on_joinplayer(function(player)
 	minetest.after(0, set_hud, player)
+	minetest.after(dlimit, u_inv_hud_step, player:get_player_name())
 end)
 
+function u_inv_hud_step(name)
+	local p = minetest.get_player_by_name(name)
+	if not p then return end
+
+	p:hud_change(huds[name], 'text', "")
+	minetest.after(dlimit, u_inv_hud_step, name)
+end
+
 minetest.register_globalstep(function(dtime)
 	for _, player in pairs(minetest.get_connected_players()) do
 		local player_name = player:get_player_name()
 		local wstack = player:get_wielded_item():get_name()
 
-		if dtimes[player_name] and dtimes[player_name] < dlimit then
-			dtimes[player_name] = dtimes[player_name] + dtime
-			if dtimes[player_name] > dlimit and huds[player_name] then
-				player:hud_change(huds[player_name], 'text', "")
-			end
-		end
-
 		if wstack ~= wield[player_name] then
 			wield[player_name] = wstack
-			dtimes[player_name] = 0
 			if huds[player_name] then
 				local def = minetest.registered_items[wstack]
 				local desc = def and def.description or ""