src: use sizeof(var) instead of sizeof(type)

Change `memset(&s, 0, sizeof(type))` to `memset(&s, 0, sizeof(s))`.
The former is dangerous when the type of `s` changes.

PR-URL: #27038
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>

src/cares_wrap.cc

@@ -1969,7 +1969,7 @@ void GetAddrInfo(const FunctionCallbackInfo<Value>& args) {
                                                        args[4]->IsTrue());
 
   struct addrinfo hints;
-  memset(&hints, 0, sizeof(struct addrinfo));
+  memset(&hints, 0, sizeof(hints));
   hints.ai_family = family;
   hints.ai_socktype = SOCK_STREAM;
   hints.ai_flags = flags;