Fixup forgotten type adjustment

Author: oli-obk

src/shims/foreign_items.rs

@@ -56,7 +56,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                     .write_bytes(ptr.into(), iter::repeat(0u8).take(size as usize))
                     .unwrap();
             }
-            Scalar::Ptr(ptr)
+            ptr
         }
     }