readline: fix some strict audit failures.

Formula/readline.rb

@@ -1,5 +1,3 @@
-require "formula"
-
 class Readline < Formula
   homepage "http://tiswww.case.edu/php/chet/readline/rltop.html"
   url "http://ftpmirror.gnu.org/readline/readline-6.3.tar.gz"
@@ -15,7 +13,7 @@ class Readline < Formula
     sha1 "e84f9cd95503b284651ef24bc8e7da30372687d3" => :lion
   end
 
-  keg_only :shadowed_by_osx, <<-EOS
+  keg_only :shadowed_by_osx, <<-EOS.undent
     OS X provides the BSD libedit library, which shadows libreadline.
     In order to prevent conflicts when programs look for libreadline we are
     defaulting this GNU Readline installation to keg-only.
@@ -35,7 +33,7 @@ EOS
   def install
     ENV.universal_binary
     system "./configure", "--prefix=#{prefix}", "--enable-multibyte"
-    system "make install"
+    system "make", "install"
 
     # The 6.3 release notes say:
     #   When creating shared libraries on Mac OS X, the pathname written into the