missed stderr

Author: William Utter

tests/ui/const-generics/generic_const_exprs/const_kind_expr/issue_114151.rs

@@ -19,7 +19,7 @@ where
     //~^^ ERROR: unconstrained generic constant
     //~^^^ ERROR: function takes 1 generic argument but 2 generic arguments were supplied
     //~^^^^ ERROR: unconstrained generic constant
-    //~^^^^^ ERROR: unconstrained generic constant `{const expr}`
+    //~^^^^^ ERROR: unconstrained generic constant `L + 1 + L`
 }
 
 fn main() {}