Revert "Improve check for buffer-local mapping for K"

This reverts commit 9ead258.

Closes #1

ftplugin/tmux.vim

@@ -9,12 +9,7 @@ set cpo&vim
 setlocal comments=:#
 setlocal commentstring=#\ %s
 
-if v:version > 704 || v:version == 704 && has('patch32')
-  let s:map_dict = maparg('K', 'n', 0, 1)
-  if empty(s:map_dict) || ! s:map_dict['buffer']
-    nnoremap <silent><buffer> K :call tmux#man()<CR>
-  endif
-elseif maparg('K','n') ==# ''
+if maparg('K','n') ==# ''
   nnoremap <silent><buffer> K :call tmux#man()<CR>
 endif