corrected varname that started with number and broke templating

test/integration/roles/test_filters/tasks/main.yml

@@ -37,12 +37,12 @@
 
 - name: 9851 - Compare generated json to known good
   shell: diff -w {{output_dir}}/9851.out {{output_dir}}/9851.txt
-  register: 9851_diff_result
+  register: diff_result_9851
 
 - name: 9851 - verify generated file matches known good
   assert:  
     that: 
-        - '9851_diff_result.stdout == ""' 
+        - 'diff_result_9851.stdout == ""'
 
 - name: fill in a basic template
   template: src=foo.j2 dest={{output_dir}}/foo.templated mode=0644