docs(tutorial): fix controller unit tests to match phonecat / avoid ReferenceError

fix 'ReferenceError: PhoneDetailCtrl is not defined' & 'ReferenceError: PhoneListCtrl is not defined' in Karma unit tests

Closes angular#7421

Author: TimvdEijnden

docs/content/tutorial/step_11.ngdoc

@@ -202,7 +202,7 @@ describe('PhoneCat controllers', function() {
           respond([{name: 'Nexus S'}, {name: 'Motorola DROID'}]);
 
       scope = $rootScope.$new();
-      ctrl = $controller(PhoneListCtrl, {$scope: scope});
+      ctrl = $controller('PhoneListCtrl', {$scope: scope});
     }));
 
 
@@ -237,7 +237,7 @@ describe('PhoneCat controllers', function() {
 
       $routeParams.phoneId = 'xyz';
       scope = $rootScope.$new();
-      ctrl = $controller(PhoneDetailCtrl, {$scope: scope});
+      ctrl = $controller('PhoneDetailCtrl', {$scope: scope});
     }));