Fix broken links in in docs_src/ (missing $)

  Delete OpMatcher and op_type from guide (they have been deleted from the public api).
Change: 150267754

tensorflow/docs_src/api_guides/python/contrib.graph_editor.md

@@ -170,11 +170,6 @@ which to operate must always be given explicitly. This is the reason why
 *   @{tf.contrib.graph_editor.copy_with_input_replacements}
 *   @{tf.contrib.graph_editor.graph_replace}
 
-## Module: match
-
-*   @{tf.contrib.graph_editor.op_type}
-*   @{tf.contrib.graph_editor.OpMatcher}
-
 ## Useful aliases
 
 *   @{tf.contrib.graph_editor.ph}