Remove unused resource controller methods

These methods aren't necessary since commit 71601bd3f.

app/controllers/admin/poll/polls_controller.rb

@@ -72,8 +72,4 @@ class Admin::Poll::PollsController < Admin::Poll::BaseController
 
       [*attributes, *report_attributes, translation_params(Poll)]
     end
-
-    def resource
-      @poll ||= Poll.find(params[:id])
-    end
 end

app/controllers/admin/poll/questions/answers_controller.rb

@@ -46,9 +46,4 @@ class Admin::Poll::Questions::AnswersController < Admin::Poll::BaseController
 
       [*attributes, translation_params(Poll::Question::Answer)]
     end
-
-    def resource
-      load_answer unless @answer
-      @answer
-    end
 end

app/controllers/admin/poll/questions_controller.rb

@@ -62,8 +62,4 @@ class Admin::Poll::QuestionsController < Admin::Poll::BaseController
     def search_params
       params.permit(:poll_id, :search)
     end
-
-    def resource
-      @poll_question ||= Poll::Question.find(params[:id])
-    end
 end