systemd: add osd id to service description

systemd: add osd id to service description

So, instead of logging this:

Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.
Jul 01 13:51:04 localhost systemd[1]: Failed to start Ceph object storage daemon.

We see this, which is a lot more useful:

Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.27.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.32.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.29.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.31.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.23.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.24.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.25.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.30.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.28.
Jul 01 13:59:32 localhost systemd[1]: Failed to start Ceph object storage daemon osd.22.