[tune] Fix for keras threading (#5517)

python/ray/tune/examples/utils.py

@@ -2,6 +2,7 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
+import tensorflow as tf
 import keras
 from keras.datasets import mnist
 from keras import backend as K
@@ -52,8 +53,8 @@ def set_keras_threads(threads):
     # We set threads here to avoid contention, as Keras
     # is heavily parallelized across multiple cores.
     K.set_session(
-        K.tf.Session(
-            config=K.tf.ConfigProto(
+        tf.Session(
+            config=tf.ConfigProto(
                 intra_op_parallelism_threads=threads,
                 inter_op_parallelism_threads=threads)))