tls: use correct class name in deprecation message

`tls.Socket` does not exist, and the deprecation message
should refer to `tls.TLSSocket` (like the documentation
for the deprecation message already does).

PR-URL: https://github.com/nodejs/node/pull/17561


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>