Fix :io.columns calls

Author: ericmj

lib/iex/lib/iex.ex

@@ -338,7 +338,7 @@ defmodule IEx do
   Get the width to be used on helpers with a maximum (and default) of 80 chars.
   """
   def width do
-    case :io.columns(:standard_input) do
+    case :io.columns() do
       {:ok, width} -> min(width, 80)
       {:error, _}  -> 80
     end

lib/mix/lib/mix/tasks/help.ex

@@ -97,7 +97,7 @@ defmodule Mix.Tasks.Help do
   end
 
   defp width() do
-    case :io.columns(:standard_input) do
+    case :io.columns() do
       {:ok, width} -> min(width, 80)
       {:error, _}  -> 80
     end