Internal network code cleanup

Author: sharadraju

lib/thin/sqlnet/ntTcp.js

@@ -352,13 +352,7 @@ class NTTCP {
   async pauseWrite() {
     this.checkErr();
     if (this.needsDrain) {
-      await new Promise((resolve) => {
-        this.waiter = resolve;
-        this.stream.once('drain', () => {
-          resolve();
-          this.waiter = null;
-        });
-      });
+      await new Promise((resolve) => this.stream.once('drain', resolve));
       this.checkErr();
     } else {
       await new Promise((resolve) => Timers.setImmediate(resolve));