pdch: Use llist_first_entry() API

Change-Id: I96e7188ecf7d2cfc54598975f8d538e7aa94401a
diff --git a/src/pdch.cpp b/src/pdch.cpp
index c69c45c..96bab54 100644
--- a/src/pdch.cpp
+++ b/src/pdch.cpp
@@ -179,7 +179,7 @@
 
 	if (llist_empty(&paging_list))
 		return NULL;
-	pag = llist_entry(paging_list.next, struct gprs_rlcmac_paging, list);
+	pag = llist_first_entry(&paging_list, struct gprs_rlcmac_paging, list);
 	llist_del(&pag->list);
 
 	return pag;