tls: refactor to use validateFunction

Use validateFunction to remove duplicate implementation.
Plus, remove `assert()` statement because validateFunction
has the same purpose.

PR-URL: #49422
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Debadree Chatterjee <debadree333@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/_tls_wrap.js

@@ -834,10 +834,7 @@ TLSSocket.prototype._init = function(socket, wrap) {
     ssl.handshakes = 0;
 
     if (options.ALPNCallback) {
-      if (typeof options.ALPNCallback !== 'function') {
-        throw new ERR_INVALID_ARG_TYPE('options.ALPNCallback', 'Function', options.ALPNCallback);
-      }
-      assert(typeof options.ALPNCallback === 'function');
+      validateFunction(options.ALPNCallback, 'options.ALPNCallback');
       this[kALPNCallback] = options.ALPNCallback;
       ssl.ALPNCallback = callALPNCallback;
       ssl.enableALPNCb();