net: only defer _final call when connecting

lib/net.js

@@ -507,7 +507,7 @@ Socket.prototype._unrefTimer = function _unrefTimer() {
 // sent out to the other side.
 Socket.prototype._final = function(cb) {
   // If still connecting - defer handling `_final` until 'connect' will happen
-  if (this.pending) {
+  if (this.connecting) {
     debug('_final: not yet connected');
     return this.once('connect', () => this._final(cb));
   }

test/parallel/test-net-end-without-connect.js

@@ -20,8 +20,11 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const net = require('net');
+const assert = require('assert');
 
 const sock = new net.Socket();
-sock.end();  // Should not throw.
+sock.end(common.mustCall(() => {
+  assert.strictEqual(sock.writable, false);
+}));