PERF: Remove `Object#present?` check introduced in e0d5d9670a.

lib/filter_best_posts.rb

@@ -15,7 +15,7 @@ class FilterBestPosts
   def filter
     @posts =
       if @min_replies && @topic.posts_count < @min_replies + 1
-        []
+        Post.none
       else
         filter_posts_liked_by_moderators
         setup_posts

lib/topic_view.rb

@@ -66,7 +66,7 @@ class TopicView
 
     filter_posts(options)
 
-    if @posts.present?
+    if @posts
       if (added_fields = User.whitelisted_user_custom_fields(@guardian)).present?
         @user_custom_fields = User.custom_fields_for_ids(@posts.pluck(:user_id), added_fields)
       end
@@ -388,7 +388,7 @@ class TopicView
 
     max = [max, post_count].min
 
-    return @posts = [] if min > max
+    return @posts = Post.none if min > max
 
     min = [[min, max].min, 0].max