Add semicolon

Co-Authored-By: Ralf Jung <post@ralfj.de>

src/helpers.rs

@@ -87,7 +87,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         // any additional checks - it's okay if the pointer is invalid,
         // since we wouldn't actually be writing to it.
         if len == 0 {
-            return Ok(())
+            return Ok(());
         }
         let this = self.eval_context_mut();