fix flow warning and typo

Differential Revision: D5796855

fbshipit-source-id: 455c2539b111e8e7aca44d762cefabf764171beb

Libraries/Linking/Linking.js

@@ -82,7 +82,7 @@ const LinkingManager = Platform.OS === 'android' ?
  *   return [RCTLinkingManager application:application openURL:url options:options];
  * }
  * ```
- * 
+ *
  * If you're targeting iOS 8.x or older, you can use the following code instead:
  *
  * ```