fix typo in comments

Author: sllethe

src/lib/list/list-option.ts

@@ -69,7 +69,7 @@ export class MdListOption implements AfterContentInit, OnDestroy, Focusable {
 
   /**
    * Whether the ripple effect on click should be disabled. This applies only to list items that are
-   * part of a nav list. The value of `disableRipple` on the `md-nav-list` overrides this flag.
+   * part of a selection list. The value of `disableRipple` on the `md-nav-list` overrides this flag
    */
   @Input()
   get disableRipple() { return this._disableRipple; }