dlm: fix pending remove if msg allocation fails

dlm: fix pending remove if msg allocation fails

This patch unsets ls_remove_len and ls_remove_name if a message
allocation of a remove messages fails. In this case we never send a
remove message out but set the per ls ls_remove_len ls_remove_name
variable for a pending remove. Unset those variable should indicate
possible waiters in wait_pending_remove() that no pending remove is
going on at this moment.

Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>