(#6830) Fix stat method calls to not use an unneeded argument

With this change under ruby 1.9.2 the number of failing specs goes from
2003 to 635. Also, puppet apply and master both seem to work. Agent
still has OpenSSL issues.

Ruby 1.8 doesn't complain if you pass arguments to a runtime defined
method that doesn't take arguments. Ruby 1.9 does

class Foo
  define_method('bar') do
    puts 'baz'
  end
end

Foo.new.bar("idonttakearguments")

In Ruby 1.8 this prints: baz

In Ruby 1.9 this errors with: 19_test.rb:3:in `block in <class:Foo>': wrong
number of arguments (1 for 0) (ArgumentError)

Reviewed-by: