fix typo

Author: MorvanZhou

kerasTUT/6-CNN_example.py

@@ -23,7 +23,7 @@
 from keras.optimizers import Adam
 
 # download the mnist to the path '~/.keras/datasets/' if it is the first time to be called
-# X shape (60,000 28x28), y shape (10,000, )
+# training X shape (60000, 28x28), Y shape (60000, ). test X shape (10000, 28x28), Y shape (10000, )
 (X_train, y_train), (X_test, y_test) = mnist.load_data()
 
 # data pre-processing