fs: dlm: remove unused processed_nodes

The variable processed_nodes is not being used by commit 1696c75f
("fs: dlm: add send ack threshold and append acks to msgs"). This patch
removes the leftover of this commit.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lowcomms.c

@@ -863,7 +863,6 @@ struct dlm_processed_nodes {
 static void process_dlm_messages(struct work_struct *work)
 {
 	struct processqueue_entry *pentry;
-	LIST_HEAD(processed_nodes);
 
 	spin_lock(&processqueue_lock);
 	pentry = list_first_entry_or_null(&processqueue,