Rename list_* function and file to flist_ to avoid conflict with FreeBSD

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/verify.c b/verify.c
index d602534..680e491 100644
--- a/verify.c
+++ b/verify.c
@@ -639,9 +639,9 @@
 
 		ipo = rb_entry(n, struct io_piece, rb_node);
 		rb_erase(n, &td->io_hist_tree);
-	} else if (!list_empty(&td->io_hist_list)) {
-		ipo = list_entry(td->io_hist_list.next, struct io_piece, list);
-		list_del(&ipo->list);
+	} else if (!flist_empty(&td->io_hist_list)) {
+		ipo = flist_entry(td->io_hist_list.next, struct io_piece, list);
+		flist_del(&ipo->list);
 	}
 
 	if (ipo) {