Revert "Update util.rb to fix closing of file."

This is broken and results in not closing any file descriptors.

Author: ekohl

lib/puppet/util.rb

@@ -479,7 +479,7 @@ def safe_posix_fork(stdin = $stdin, stdout = $stdout, stderr = $stderr, &block)
 
       begin
         Dir.foreach('/proc/self/fd') do |f|
-          if %{^\d+$}.match?(f) && f.to_i >= 3
+          if f != '.' && f != '..' && f.to_i >= 3
             begin
               IO.new(f.to_i).close
             rescue