chore: fix linting error

Author: crisbeto

src/lib/select/select.ts

@@ -299,7 +299,7 @@ export class MdSelect implements AfterContentInit, ControlValueAccessor, OnDestr
 
   constructor(private _element: ElementRef, private _renderer: Renderer,
               private _viewportRuler: ViewportRuler, private _changeDetectorRef: ChangeDetectorRef,
-              private _scrollDispatcher: ScrollDispatcher, @Optional() private _dir: Dir, 
+              private _scrollDispatcher: ScrollDispatcher, @Optional() private _dir: Dir,
               @Self() @Optional() public _control: NgControl,
               @Attribute('tabindex') tabIndex: string) {