[master] d083cb095 v1l: Don't mention timeouts on failed writes

[Dridi Boukelmoune]

commit d083cb095f8a676f331e2544815fc7ac39c7b75c
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Wed Jun 30 14:46:33 2021 +0200

    v1l: Don't mention timeouts on failed writes
    
    This has confused at least one user troubleshooting this area.

diff --git a/bin/varnishd/http1/cache_http1_line.c b/bin/varnishd/http1/cache_http1_line.c
index c275c92ef..52e1c88b0 100644
--- a/bin/varnishd/http1/cache_http1_line.c
+++ b/bin/varnishd/http1/cache_http1_line.c
@@ -222,9 +222,12 @@ V1L_Flush(const struct worker *wrk)
 			 * prevent slowloris attacks
 			 */
 
-			VSLb(v1l->vsl, SLT_Debug,
-			    "Hit idle send timeout, wrote = %zd/%zd; retrying",
-			    i, v1l->liov);
+			if (errno == EWOULDBLOCK) {
+				VSLb(v1l->vsl, SLT_Debug,
+				    "Hit idle send timeout, "
+				    "wrote = %zd/%zd; retrying",
+				    i, v1l->liov);
+			}
 
 			if (i > 0)
 				v1l_prune(v1l, i);