Update Rakefile

Co-authored-by: Benjamin Quorning <22333+bquorning@users.noreply.github.com>

Rakefile

@@ -75,7 +75,7 @@ task confirm_documentation: :generate_cops_documentation do
   stdout, _stderr, status =
     Open3.capture3('git diff --exit-code docs/')
 
-  unless process.to_i.zero?
+  unless status.success?
     puts 'Documentation is out of sync:'
     puts stdin
     raise 'Please run `rake generate_cops_documentation` ' \