corrected "check_graph" to "summarize_graph" (tensorflow#8896)

* corrected "check_graph" to "summarize_graph"

"check_graph" may have been the previous name for "summarize_graph"
the surrounding text suggests that both refer to the same tool

* Update README.md

Author: Androbin

tensorflow/tools/graph_transforms/README.md

@@ -103,7 +103,7 @@ output layers of the model are. The best source for these is the model training
 process, where for a classifier the inputs will be the nodes that receive the
 data from the training set, and the output will be the predictions. If you're
 unsure, the
-[summarize_graph](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/graph_transforms/summarize_graph_main.cc)
+[`summarize_graph`](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/graph_transforms/summarize_graph_main.cc)
 tool can inspect the model and provide guesses about likely input and output nodes,
 as well as other information that's useful for debugging. Here's an example of
 how to use it on the [Inception V3
@@ -315,7 +315,7 @@ themselves contain commas (for example shape definitions).
 The --inputs and --outputs are shared across all transforms, since it's common
 to need to know what the ingoing and outgoing nodes in the graph are. You should
 make sure you set these correctly before calling the graph transform tool, and
-if you're in doubt check with the model's author, or use the `check_graph` tool
+if you're in doubt check with the model's author, or use the [`summarize_graph`](https://github.com/tensorflow/tensorflow/tree/master/tensorflow/tools/graph_transforms#inspecting-graphs) tool
 to examine likely inputs and outputs.
 
 All transforms can be passed the `ignore_errors` flag, with the value set to