Tutorial: Fix destination of link from Step 6 to Step 5

The link in Step 6 (to "Testing Support") clearly refers to Exercise 2.
Fix the location to which the link jumps.

Help/guide/tutorial/Installing and Testing.rst

@@ -1,8 +1,6 @@
 Step 5: Installing and Testing
 ==============================
 
-.. _`Tutorial Testing Support`:
-
 Exercise 1 - Install Rules
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -154,6 +152,8 @@ are similar. To the end of the top-level ``CMakeLists.txt`` we add:
 That is all that is needed to create a basic local
 install of the tutorial.
 
+.. _`Tutorial Testing Support`:
+
 Exercise 2 - Testing Support
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^