Tidy up the free code in DeleteAllClasses() for CIP class and meta class

Try to make the memory free code in DeleteAllClasses() for CIP class and
meta class more concise.

Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>

source/src/cip/cipmessagerouter.c

@@ -289,32 +289,25 @@ void DeleteAllClasses(void) {
       CipFree(instance_to_delete);
     }
 
-    /*clear meta class data*/
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.cip_class
-      ->class_name);
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.cip_class
-      ->services);
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.cip_class
-      ->get_single_bit_mask);
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.cip_class
-      ->set_bit_mask);
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.cip_class
-      ->get_all_bit_mask);
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.cip_class);
-    /*clear class data*/
-    CipFree(message_router_object_to_delete->cip_class->get_single_bit_mask);
-    CipFree(message_router_object_to_delete->cip_class->set_bit_mask);
-    CipFree(message_router_object_to_delete->cip_class->get_all_bit_mask);
-    CipFree(
-      message_router_object_to_delete->cip_class->class_instance.attributes);
-    CipFree(message_router_object_to_delete->cip_class->services);
-    CipFree(message_router_object_to_delete->cip_class);
+    /* free meta class data*/
+    CipClass *meta_class =
+      message_router_object_to_delete->cip_class->class_instance.cip_class;
+    CipFree(meta_class->class_name);
+    CipFree(meta_class->services);
+    CipFree(meta_class->get_single_bit_mask);
+    CipFree(meta_class->set_bit_mask);
+    CipFree(meta_class->get_all_bit_mask);
+    CipFree(meta_class);
+
+    /* free class data*/
+    CipClass *cip_class = message_router_object_to_delete->cip_class;
+    CipFree(cip_class->get_single_bit_mask);
+    CipFree(cip_class->set_bit_mask);
+    CipFree(cip_class->get_all_bit_mask);
+    CipFree(cip_class->class_instance.attributes);
+    CipFree(cip_class->services);
+    CipFree(cip_class);
+    /* free message router object */
     CipFree(message_router_object_to_delete);
   }
   g_first_object = NULL;