Restructure mode conponent

lua/lualine/components/mode.lua

@@ -1,7 +1,6 @@
 -- Copyright (c) 2020-2021 hoob3rt
 -- MIT license, see LICENSE for more details.
 
-local function mode()
 local mode_map = {
   ['n']    = 'NORMAL',
   ['no']   = 'O-PENDING',
@@ -33,12 +32,10 @@ local function mode()
   ['!']    = 'SHELL',
   ['t']    = 'TERMINAL',
 }
-  local function get_mode()
+local function mode()
   local mode_code = vim.api.nvim_get_mode().mode
   if mode_map[mode_code] == nil then return mode_code end
   return mode_map[mode_code]
 end
-  return get_mode()
-end
 
 return mode