[vim] tab split instead of tabedit

plugin/fzf.vim

@@ -358,7 +358,7 @@ endfunction
 
 let s:default_action = {
   \ 'ctrl-m': 'e',
-  \ 'ctrl-t': 'tabedit',
+  \ 'ctrl-t': 'tab split',
   \ 'ctrl-x': 'split',
   \ 'ctrl-v': 'vsplit' }