[6.0] 5664571e0 No idea how I overlooked that wl was unsigned.

[Dridi Boukelmoune]

commit 5664571e0bbfe291799a516d84acaa534bb9dd98
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Wed Apr 11 08:27:43 2018 +0000

    No idea how I overlooked that wl was unsigned.
    
    Doesn't change the logic however.

diff --git a/bin/varnishd/http1/cache_http1_fsm.c b/bin/varnishd/http1/cache_http1_fsm.c
index c88fffdb6..650690950 100644
--- a/bin/varnishd/http1/cache_http1_fsm.c
+++ b/bin/varnishd/http1/cache_http1_fsm.c
@@ -247,7 +247,7 @@ http1_reembark(struct worker *wrk, struct req *req)
 static int v_matchproto_(vtr_minimal_response_f)
 http1_minimal_response(struct req *req, uint16_t status)
 {
-	size_t wl, l;
+	ssize_t wl, l;
 	char buf[80];
 	const char *reason;