Fixing the logic problem

du4/a_train.c

@@ -63,7 +63,7 @@ struct car* clear_train(struct car* first, const char* target) {
     }
     struct car* prev= NULL;
     struct car* temp = first;
-    while (temp->next)
+    while (temp)
     { 
         if(strcmp(temp->value, target) == 0){
          struct car* targetNode = temp;