src: fix may be uninitialized warning in n-api

PR-URL: #21898
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Trivikram Kamat <[email protected]>
Reviewed-By: Jon Moss <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>

src/node_api.cc

@@ -3849,7 +3849,7 @@ class TsFn: public node::AsyncResource {
   }
 
   void DispatchOne() {
-    void* data;
+    void* data = nullptr;
     bool popped_value = false;
     bool idle_stop_failed = false;