Update test output

testsuite/tests/ghc-regress/deriving/should_fail/drvfail002.stderr

 
 drvfail002.hs:15:0:
     Ambiguous constraint `X T c'
-	At least one of the forall'd type variables mentioned by the constraint
-	must be reachable from the type after the '=>'
+        At least one of the forall'd type variables mentioned by the constraint
+        must be reachable from the type after the '=>'
     In the instance declaration for `Show T'
-
-drvfail002.hs:18:0:
-    No instance for (X T c)
-      arising from the 'deriving' clause of a data type declaration
-		   at drvfail002.hs:18:0-25
-    Possible fix: add an instance declaration for (X T c)
-    When deriving the instance for (Show S)