`lint` should not show warnings when passing multiples `--files`

[PowerKiKi]

🐞 Bug report

Command (mark with an x)

- [x] lint

Is this a regression?

AFAIK it's always been that way.

Description

The lint command will output warning messages when passing multiple files. I expect to see no warning at all when the command is used as it was intended.

This directly related to #7612 (comment)

🔬 Minimal Reproduction

Create a new project from scratch and run lint with two (or more) specific files:

ng new app # accepts all default values
cd app
ng lint --files=src/app/app.component.ts  --files=src/app/app.module.ts

🔥 Exception or Error

The output will be:

Option "files" was already specified with value ["src/app/app.component.ts"]. The new value ["src/app/app.component.ts","src/app/app.module.ts"] will override it.
Linting "app"...
All files pass linting.

But I expected it to be:

Linting "app"...
All files pass linting.

🌍 Your Environment

Angular CLI: 8.3.5
Node: 10.16.3
OS: linux x64
Angular: 8.2.7
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.803.5
@angular-devkit/build-angular     0.803.5
@angular-devkit/build-optimizer   0.803.5
@angular-devkit/build-webpack     0.803.5
@angular-devkit/core              8.3.5
@angular-devkit/schematics        8.3.5
@angular/cli                      8.3.5
@ngtools/webpack                  8.3.5
@schematics/angular               8.3.5
@schematics/update                0.803.5
rxjs                              6.4.0
typescript                        3.5.3
webpack                           4.39.2