Fix some missed size_t updates

Reviewed-by: Rich Salz <rsalz@openssl.org>
diff --git a/ssl/pqueue.c b/ssl/pqueue.c
index b447e1d..9ff4132 100644
--- a/ssl/pqueue.c
+++ b/ssl/pqueue.c
@@ -141,7 +141,7 @@
     return ret;
 }
 
-int pqueue_size(pqueue *pq)
+size_t pqueue_size(pqueue *pq)
 {
     pitem *item = pq->items;
     int count = 0;