Remove unneeded return (#950)

add_to_app/books/README.md

@@ -2,7 +2,7 @@
 
 Mimics a real world use-case of embedding Flutter into an existing Android app
 and demonstrates using [Pigeon](https://pub.dev/packages/pigeon) to communicate
-between Fluter and the host application.
+between Flutter and the host application.
 
 ## Description
 

add_to_app/books/flutter_module_books/lib/api.dart

@@ -165,8 +165,6 @@ class HostBookApi {
         message: error['message'] as String?,
         details: error['details'],
       );
-    } else {
-      return;
     }
   }
 
@@ -190,8 +188,6 @@ class HostBookApi {
         message: error['message'] as String?,
         details: error['details'],
       );
-    } else {
-      return;
     }
   }
 }