Fix var name in gptq tutorial

tutorials/notebooks/mct_features_notebooks/keras/example_keras_mobilenet_gptq.ipynb

@@ -388,7 +388,7 @@
    "outputs": [],
    "source": [
     "quantized_model.compile(loss=keras.losses.SparseCategoricalCrossentropy(), metrics=\"accuracy\")\n",
-    "quantized_accuracy = float_model.evaluate(val_dataset)\n",
+    "quantized_accuracy = quantized_model.evaluate(val_dataset)\n",
     "print(f\"Quantized model's Top 1 accuracy on the Imagenet validation set: {(quantized_accuracy[1] * 100):.2f}%\")"
    ]
   },