fix(script): Output snapshots list with trailing line break so that 'wc -l' can better count them (#1)

pacman-zfs-snapshot.sh

@@ -229,7 +229,7 @@ function get_snaps_in_cur_sev () {
     snap_list="$(zfs list -H -o 'name' -t snapshot "${dataset_to_query}")"
     snaps_done_by_us="$(grep -Pi -- '@'"${snap_name_prefix}${snap_field_separator}" <<<"${snap_list}")"
     snaps_in_cur_sev="$(grep -Pi -- "${snap_field_separator}"'sev:'"${severity}${snap_field_separator}" <<<"${snaps_done_by_us}")"
-    printf -- '%s' "${snaps_in_cur_sev}"
+    printf -- '%s\n' "${snaps_in_cur_sev}"
 }
 
 function do_retention () {