fs: dlm: remove unused struct 'dlm_processed_nodes'

The last use of 'dlm_processed_nodes' was removed in
commit 1696c75f ("fs: dlm: add send ack threshold and append acks to
msgs").

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lowcomms.c

@@ -858,12 +858,6 @@ static void free_processqueue_entry(struct processqueue_entry *pentry)
 	kfree(pentry);
 }
 
-struct dlm_processed_nodes {
-	int nodeid;
-
-	struct list_head list;
-};
-
 static void process_dlm_messages(struct work_struct *work)
 {
 	struct processqueue_entry *pentry;