[master] 21316e4d0 vai: fix another glitch from 84d1fc92f436e9c94d127ec45e779b36f0f7c2a7

[Nils Goroll]

commit 21316e4d05fe91c9722fc887d5146077b5d0c393
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Tue Aug 5 12:31:01 2025 +0200

    vai: fix another glitch from 84d1fc92f436e9c94d127ec45e779b36f0f7c2a7
    
    We need to increment the return value to signify that we added a viov.
    
    Potentially related to #4371

diff --git a/bin/varnishd/storage/storage_simple.c b/bin/varnishd/storage/storage_simple.c
index ab5b03ad0..05f224cdf 100644
--- a/bin/varnishd/storage/storage_simple.c
+++ b/bin/varnishd/storage/storage_simple.c
@@ -487,6 +487,7 @@ sml_ai_lease_boc(struct worker *wrk, vai_hdl vhdl, struct vscarab *scarab)
 		viov->iov.iov_base = null_iov;
 		viov->iov.iov_len = 0;
 		viov->lease = ptr2lease(hdl->last);
+		r++;
 	}
 	if (hdl->last != NULL)
 		hdl->last = NULL;