suppress only errors in init-script while determining canonical path of gitlab_workhorse_dir

lib/support/init.d/gitlab

@@ -38,7 +38,7 @@ web_server_pid_path="$pid_path/unicorn.pid"
 sidekiq_pid_path="$pid_path/sidekiq.pid"
 mail_room_enabled=false
 mail_room_pid_path="$pid_path/mail_room.pid"
-gitlab_workhorse_dir=$(cd $app_root/../gitlab-workhorse && pwd)
+gitlab_workhorse_dir=$(cd $app_root/../gitlab-workhorse 2> /dev/null && pwd)
 gitlab_workhorse_pid_path="$pid_path/gitlab-workhorse.pid"
 gitlab_workhorse_options="-listenUmask 0 -listenNetwork unix -listenAddr $socket_path/gitlab-workhorse.socket -authBackend http://127.0.0.1:8080 -authSocket $rails_socket -documentRoot $app_root/public"
 gitlab_workhorse_log="$app_root/log/gitlab-workhorse.log"