comment votes: fix error handling.

Return the comment itself and a standard error response on failure.

app/controllers/comment_votes_controller.rb

@@ -2,20 +2,17 @@ class CommentVotesController < ApplicationController
   respond_to :js, :json, :xml
   before_action :member_only
   skip_before_action :api_check
+  rescue_with CommentVote::Error, ActiveRecord::RecordInvalid, status: 422
 
   def create
     @comment = Comment.find(params[:comment_id])
     @comment_vote = @comment.vote!(params[:score])
-  rescue CommentVote::Error, ActiveRecord::RecordInvalid => x
-    @error = x
-    render status: 422
+    respond_with(@comment)
   end
 
   def destroy
     @comment = Comment.find(params[:comment_id])
     @comment.unvote!
-  rescue CommentVote::Error => x
-    @error = x
-    render status: 422
+    respond_with(@comment)
   end
 end