remove misleading comment

per aliemjay's suggestion

Author: nikomatsakis

compiler/rustc_infer/src/infer/outlives/verify.rs

@@ -250,10 +250,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
 
         // To start, collect bounds from user environment. Note that
         // parameter environments are already elaborated, so we don't
-        // have to worry about that. Comparing using `==` is a bit
-        // dubious for projections, but it will work for simple cases
-        // like `T` and `T::Item`. It may not work as well for things
-        // like `<T as Foo<'a>>::Item`.
+        // have to worry about that.
         let c_b = self.param_env.caller_bounds();
         let param_bounds = self.collect_outlives_from_predicate_list(erased_ty, c_b.into_iter());