Remove leftover comment

Author: oli-obk

src/librustc/mir/interpret/allocation.rs

@@ -120,8 +120,6 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
         ptr: Pointer<Tag>,
         required_align: Align
     ) -> EvalResult<'tcx> {
-        // Check non-NULL/Undef, extract offset
-
         // check this is not NULL -- which we can ensure only if this is in-bounds
         let size = Size::from_bytes(self.bytes.len() as u64);
         if ptr.offset > size {