tls: refactor tls_wrap.cc

Store the result of excetuting the function in variable. Instead of
excetuting it for multiple times.

PR-URL: #30303
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

src/tls_wrap.cc

@@ -1141,12 +1141,11 @@ void TLSWrap::Initialize(Local<Object> target,
   env->SetProtoMethod(t, "getServername", GetServername);
   env->SetProtoMethod(t, "setServername", SetServername);
 
-  env->set_tls_wrap_constructor_function(
-      t->GetFunction(env->context()).ToLocalChecked());
+  Local<Function> fn = t->GetFunction(env->context()).ToLocalChecked();
 
-  target->Set(env->context(),
-              tlsWrapString,
-              t->GetFunction(env->context()).ToLocalChecked()).Check();
+  env->set_tls_wrap_constructor_function(fn);
+
+  target->Set(env->context(), tlsWrapString, fn).Check();
 }
 
 }  // namespace node