posts: fix incorrect post counts for -pool:, -fav: searches

Fix `-pool:1234` and `-fav:evazion` searches incorrectly returning the
same post count as `pool:1234` and `fav:evazion` searches.

test/unit/post_query_builder_test.rb

@@ -1480,14 +1480,21 @@ class PostQueryBuilderTest < ActiveSupport::TestCase
 
         assert_fast_count(3, "pool:#{pool.id}")
         assert_fast_count(3, "pool:#{pool.name}")
+        assert_fast_count(3, "ordpool:#{pool.id}")
+        assert_fast_count(3, "ordpool:#{pool.name}")
+
+        assert_fast_count(Post.count, "-pool:#{pool.id}")
+        assert_fast_count(Post.count, "-pool:#{pool.name}")
       end
 
       should "return the correct favorite count for a fav:<name> search" do
         fav = create(:favorite)
-        fav.user.update!(favorite_count: 1)
+        User.where(id: fav.user).update_all(favorite_count: 42) # XXX favorite_count is readonly; update it this way to bypass the readonly check.
 
-        assert_fast_count(1, "fav:#{fav.user.name}")
-        assert_fast_count(1, "ordfav:#{fav.user.name}")
+        assert_fast_count(42, "fav:#{fav.user.name}")
+        assert_fast_count(42, "ordfav:#{fav.user.name}")
+
+        assert_fast_count(1, "-fav:#{fav.user.name}")
       end
 
       should "return the correct favorite count for a fav:<name> search for a user with private favorites" do