dlm: fix format seq ops type 4

This patch fixes to set the type 4 format ops in case of table_open4().
It got accidentially changed by commit 541adb0d ("fs: dlm: debugfs
for queued callbacks") and since them toss debug dumps the same format
as format 5 that are the queued ast callbacks for lkbs.

Fixes: 541adb0d ("fs: dlm: debugfs for queued callbacks")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>