src: don't point to out of scope variable

Coverity reported this. The addr pointer is passed to
req_wrap->Dispatch(). By the time this happens, the value
that addr points to, addr_storage, is out of scope. This
commit remedies that.

PR-URL: #27070
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>

src/udp_wrap.cc

@@ -451,9 +451,9 @@ void UDPWrap::DoSend(const FunctionCallbackInfo<Value>& args, int family) {
   req_wrap->msg_size = msg_size;
 
   int err = 0;
+  struct sockaddr_storage addr_storage;
   sockaddr* addr = nullptr;
   if (sendto) {
-    struct sockaddr_storage addr_storage;
     const unsigned short port = args[3].As<Uint32>()->Value();
     node::Utf8Value address(env->isolate(), args[4]);
     err = sockaddr_for_family(family, address.out(), port, &addr_storage);