Fix linter

Author: errm

lib/fluent/plugin/in_systemd.rb

@@ -35,7 +35,7 @@ def shutdown
     private
 
     def init_journal
-      @journal.close if @journal # rubocop:disable Style/SafeNavigation
+      @journal.close if @journal
       @journal = Systemd::Journal.new(path: @path)
       # make sure initial call to wait doesn't return :invalidate
       # see https://github.com/ledbettj/systemd-journal/issues/70