updated checkmode for update-rc.d

fixes #4146

lib/ansible/modules/system/service.py

@@ -780,6 +780,7 @@ class LinuxService(Service):
                     action = 'enable'
                     klinks = glob.glob('/etc/rc?.d/K??' + self.name)
                     if not klinks:
+                        if not self.module.check_mode:
                             (rc, out, err) = self.execute_command("%s %s defaults"  % (self.enable_cmd, self.name))
                             if rc != 0:
                                 if err:
@@ -789,9 +790,7 @@ class LinuxService(Service):
                 else:
                     action = 'disable'
 
-                if self.module.check_mode:
-                    rc = 0
-                    return
+                if not self.module.check_mode:
                     (rc, out, err) = self.execute_command("%s %s %s"  % (self.enable_cmd, self.name, action))
                     if rc != 0:
                         if err: