~/.vimrc: fix vim complaining about scope.

don't know why this suddenly changed.

.vimrc

	Bundle 'kchmck/vim-coffee-script'
	Bundle 'junegunn/goyo.vim'
	function! g:goyo_before()
	function! s:goyo_before()
		set noshowmode
	endfunction
	function! g:goyo_after()
	function! s:goyo_after()
		set showmode
	endfunction
	let g:goyo_callbacks = [function('g:goyo_before'), function('g:goyo_after')]
	let g:goyo_callbacks = [function('s:goyo_before'), function('s:goyo_after')]
endif
" Have syntax highlighting and non-vi features