Enable no-var-keyword tslint rule

extensions/typescript-language-features/src/typescriptServiceClient.ts

@@ -81,6 +81,7 @@ export default class TypeScriptServiceClient extends Disposable implements IType
 		this.pathSeparator = path.sep;
 		this.lastStart = Date.now();
 
+		// tslint:disable-next-line: no-var-keyword
 		var p = new Promise<void>((resolve, reject) => {
 			this._onReady = { promise: p, resolve, reject };
 		});

extensions/typescript-language-features/src/utils/async.ts

@@ -35,7 +35,7 @@ export class Delayer<T> {
 			}).then(() => {
 				this.completionPromise = null;
 				this.onSuccess = null;
-				var result = this.task && this.task();
+				const result = this.task && this.task();
 				this.task = null;
 				return result;
 			});