change this failing test so that it no longer fails

I see no good way to get the code block name, not sure how we used to do
this, but it is definitely not supported by the current code.

testing/examples/babel-dangerous.org

@@ -9,9 +9,7 @@
 There is no default value assigned to =x= variable. This is not permitted
 anymore.
 
-#+name: carre(x)
-#+begin_src python
+#+name: carre
+#+begin_src python :var x
   return x*x
 #+end_src
-
-#+name: carre

testing/lisp/test-ob.el

@@ -486,7 +486,7 @@ echo \"[[file:./cv.cls]]\"
       (should
        (equal
 	'(error
-	  "variable \"x\" in block \"carre\" must be assigned a default value")
+	  "Variable \"x\" must be assigned a default value")
 	err)))))
 
 (ert-deftest test-org-babel/just-one-results-block ()