Fix wmemcheck build

Author: alexcrichton

crates/wasmtime/src/runtime/vm/instance.rs

@@ -174,7 +174,7 @@ impl Instance {
             dropped_data,
             #[cfg(feature = "wmemcheck")]
             wmemcheck_state: {
-                if req.wmemcheck {
+                if req.store.engine().config().wmemcheck {
                     let size = memory_tys
                         .iter()
                         .next()