fix assert,test=develop (#17445)

paddle/fluid/operators/cross_entropy_op.h

@@ -154,9 +154,9 @@ struct HardLabelCrossEntropyForwardFunctor {
 
   HOSTDEVICE void operator()(int64_t idx) const {
     auto label = label_[idx];
-    PADDLE_ASSERT_MSG(label >= 0 && label < feature_size_,
-                      "The label is out of the range.", label);
     if (label != ignore_index_) {
+      PADDLE_ASSERT_MSG(label >= 0 && label < feature_size_,
+                        "The label is out of the range.", label);
       auto match_x = x_[idx * feature_size_ + label];
       y_[idx] = -math::TolerableValue<T>()(real_log(match_x));
       match_x_[idx] = match_x;