[6.0] af1b06125 Duh! && not ||.

[Dridi Boukelmoune]

commit af1b061258f24fc4566a590269654c61a2506b94
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Tue Apr 10 12:54:38 2018 +0000

    Duh!  && not ||.
    
    Spotted by:     fgs

diff --git a/bin/varnishd/cache/cache_gzip.c b/bin/varnishd/cache/cache_gzip.c
index 7cb317c59..72a86dd99 100644
--- a/bin/varnishd/cache/cache_gzip.c
+++ b/bin/varnishd/cache/cache_gzip.c
@@ -317,7 +317,7 @@ vdp_gunzip(struct req *req, enum vdp_action act, void **priv,
 		req->resp_len = -1;
 
 		p = ObjGetAttr(req->wrk, req->objcore, OA_GZIPBITS, &dl);
-		if (p != NULL || dl == 32) {
+		if (p != NULL && dl == 32) {
 			u = vbe64dec(p + 24);
 			/*
 			 * If the size is non-zero AND we are the top VDP