syncoid: fix output (#48)

Reviewed-on: #48
Co-authored-by: Michael Grote <michael.grote@posteo.de>
Co-committed-by: Michael Grote <michael.grote@posteo.de>

roles/mgrote_zfs_sanoid/templates/syncoid.service.j2

@@ -9,6 +9,8 @@ OnSuccess=syncoid_mail.service
 Type=oneshot
 # check if dest-dataset is mounted (sed: entferne 1. Zeile; awk: zeige nur yes/no; grep: RC1 when != yes)
 {% for item in sanoid_syncoid_datasets_sync %}
+# print dataset
+ExecStart=/bin/sh -c 'echo "{{ item.source_dataset }}"'
 # check if target dataset is mounted
 ExecStart=/bin/sh -c '/usr/sbin/zfs get mounted {{ item.destination_mount_check }} | sed 1d | awk "{print $3}" | grep yes  > /dev/null'
 # check if source host is reachable