[master] ac9258739 vtc: Polish using the new asan feature check

[Dridi Boukelmoune]

commit ac9258739219da2bd494c66fe19c1ea30a573257
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Fri Sep 24 10:36:29 2021 +0200

    vtc: Polish using the new asan feature check

diff --git a/bin/varnishtest/tests/c00057.vtc b/bin/varnishtest/tests/c00057.vtc
index a4d1ae1ce..db3919572 100644
--- a/bin/varnishtest/tests/c00057.vtc
+++ b/bin/varnishtest/tests/c00057.vtc
@@ -2,7 +2,7 @@ varnishtest	"test sigsegv handler"
 
 # Under ASAN, the stack layout is different and STACK OVERFLOW is
 # never printed.
-feature cmd "test -z $(env | grep ASAN_OPTIONS)"
+feature !asan
 
 server s1 {
 	rxreq