dlm: remove scand leftovers

This patch removes some leftover related code from dlm_scand that was
dropped in commit b1f2381c ("dlm: drop dlm_scand kthread and use
timers").

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>