fix links

Author: MarkDaoust

samples/core/tutorials/keras/overfit_and_underfit.ipynb

@@ -117,10 +117,10 @@
       "cell_type": "markdown",
       "source": [
         "<table class=\"tfo-notebook-buttons\" align=\"left\"><td>\n",
-        "<a target=\"_blank\"  href=\"https://colab.research.google.com/github/tensorflow/models/blob/master/samples/core/get_started/overfit_and_underfit.ipynb\">\n",
+        "<a target=\"_blank\"  href=\"https://colab.research.google.com/github/tensorflow/models/blob/master/samples/core/tutorials/keras/overfit_and_underfit.ipynb\">\n",
         "    <img src=\"https://www.tensorflow.org/images/colab_logo_32px.png\" /><span>Run in Google Colab</span></a>  \n",
         "</td><td>\n",
-        "<a target=\"_blank\"  href=\"https://github.com/tensorflow/models/blob/master/samples/core/get_started/overfit_and_underfit.ipynb\"><img width=32px src=\"https://www.tensorflow.org/images/GitHub-Mark-32px.png\" /><span>View source on GitHub</span></a></td></table>"
+        "<a target=\"_blank\"  href=\"https://github.com/tensorflow/models/blob/master/samples/core/tutorials/keras/overfit_and_underfit.ipynb\"><img width=32px src=\"https://www.tensorflow.org/images/GitHub-Mark-32px.png\" /><span>View source on GitHub</span></a></td></table>"
       ]
     },
     {
@@ -755,4 +755,4 @@
       ]
     }
   ]
-}
+}