fs: dlm: use list_empty() to check last iteration

This patch will use list_empty(&ls->ls_cb_delay) to check for last list
iteration. In case of a multiply count of MAX_CB_QUEUE and the list is
empty we do a extra goto more which we can avoid by checking on
list_empty().

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

fs/dlm/ast.c

@@ -300,6 +300,7 @@ void dlm_callback_resume(struct dlm_ls *ls)
 {
 	struct dlm_lkb *lkb, *safe;
 	int count = 0, sum = 0;
+	bool empty;
 
 	clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
 
@@ -315,10 +316,11 @@ void dlm_callback_resume(struct dlm_ls *ls)
 		if (count == MAX_CB_QUEUE)
 			break;
 	}
+	empty = list_empty(&ls->ls_cb_delay);
 	mutex_unlock(&ls->ls_cb_mutex);
 
 	sum += count;
-	if (count == MAX_CB_QUEUE) {
+	if (!empty) {
 		count = 0;
 		cond_resched();
 		goto more;