test: end tls gracefully, rather than destroy

The timing of destroy between client/server is undefined, but end is
guaranteed to occur.

PR-URL: #25508
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: sam-github

test/parallel/test-tls-sni-option.js

@@ -115,6 +115,7 @@ let clientError;
 
 const server = tls.createServer(serverOptions, function(c) {
   serverResults.push({ sni: c.servername, authorized: c.authorized });
+  c.end();
 });
 
 server.on('tlsClientError', function(err) {
@@ -135,7 +136,6 @@ function startTest() {
       clientResults.push(
         client.authorizationError &&
          (client.authorizationError === 'ERR_TLS_CERT_ALTNAME_INVALID'));
-      client.destroy();
 
       next();
     });

test/parallel/test-tls-sni-server-client.js

@@ -86,6 +86,7 @@ const clientResults = [];
 
 const server = tls.createServer(serverOptions, function(c) {
   serverResults.push(c.servername);
+  c.end();
 });
 
 server.addContext('a.example.com', SNIContexts['a.example.com']);
@@ -107,7 +108,6 @@ function startTest() {
       clientResults.push(
         client.authorizationError &&
         (client.authorizationError === 'ERR_TLS_CERT_ALTNAME_INVALID'));
-      client.destroy();
 
       // Continue
       start();