Fix jupyter notebook

Author: orazve

doc/modules/ROOT/pages/tutorials/import-sample-export-gnn.adoc

@@ -238,7 +238,7 @@ print(data)
 ----
 # Do a random split of the data so that ~10% goes into a test set and the rest used for training
 transform = RandomNodeSplit(num_test=40, num_val=0)
-_ = transform(data)
+data = transform(data)
 
 # We can see that our `data` object have been extended with some masks defining the split
 print(data)

examples/import-sample-export-gnn.ipynb

@@ -373,7 +373,7 @@
    "source": [
     "# Do a random split of the data so that ~10% goes into a test set and the rest used for training\n",
     "transform = RandomNodeSplit(num_test=40, num_val=0)\n",
-    "_ = transform(data)\n",
+    "data = transform(data)\n",
     "\n",
     "# We can see that our `data` object have been extended with some masks defining the split\n",
     "print(data)\n",