message: Fix issue in `variable` docs
  A couple of doc error in `programmers_guide/variables.md`
  This fix fixes 12444.
diff: @@ -266,7 +266,7 @@ calling this function repeatedly would not work:
  ``` python
  input1 = tf.random_normal([1,10,10,32])
  input2 = tf.random_normal([1,20,20,32])
  -x = conv_relu(input1, kernel_shape=[5, 5, 1, 32], bias_shape=[32])
  +x = conv_relu(input1, kernel_shape=[5, 5, 32, 32], bias_shape=[32])
  x = conv_relu(x, kernel_shape=[5, 5, 32, 32], bias_shape = [32]) # This fails.
  ```
  @@ -278,7 +278,7 @@ however, clarifies that we want to create new variables:
  def my_image_filter(input_images):
  with tf.variable_scope("conv1"):
  # Variables created here will be named "conv1/weights", "conv1/biases".
  - relu1 = conv_relu(input_images, [5, 5, 1, 32], [32])
  + relu1 = conv_relu(input_images, [5, 5, 32, 32], [32])
  with tf.variable_scope("conv2"):
  # Variables created here will be named "conv2/weights", "conv2/biases".
  return conv_relu(relu1, [5, 5, 32, 32], [32])
  