Update const-fn-error.stderr

Author: mbartlett21

src/test/ui/consts/const-fn-error.stderr

@@ -22,8 +22,8 @@ LL |     for i in 0..x {
 note: impl defined here, but it is not `const`
   --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
    |
-LL | impl<I: Iterator> IntoIterator for I {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | impl<I: ~const Iterator> const IntoIterator for I {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error[E0658]: mutable references are not allowed in constant functions