Fix code style of regeneration-related code (mastodon#9843)

Author: Gargron

app/models/user.rb

@@ -362,7 +362,8 @@ def prepare_returning_user!
   end
 
   def regenerate_feed!
-    Redis.current.setnx("account:#{account_id}:regeneration", true) && Redis.current.expire("account:#{account_id}:regeneration", 1.day.seconds)
+    return unless Redis.current.setnx("account:#{account_id}:regeneration", true)
+    Redis.current.expire("account:#{account_id}:regeneration", 1.day.seconds)
     RegenerationWorker.perform_async(account_id)
   end
 

app/services/precompute_feed_service.rb

@@ -3,6 +3,7 @@
 class PrecomputeFeedService < BaseService
   def call(account)
     FeedManager.instance.populate_feed(account)
+  ensure
     Redis.current.del("account:#{account.id}:regeneration")
   end
 end