Fix NLL test

Author: matthewjasper

src/test/ui/type-alias-impl-trait/generic_type_does_not_live_long_enough.nll.stderr

@@ -13,10 +13,10 @@ LL |     let z: i32 = x;
    |            expected due to this
 ...
 LL | type WrongGeneric<T> = impl 'static;
-   | ------------------------------------ the found opaque type
+   |                        ------------ the found opaque type
    |
    = note:     expected type `i32`
-           found opaque type `WrongGeneric::<&{integer}>`
+           found opaque type `impl Sized`
 
 error: aborting due to 2 previous errors