Simplify r02976.vtc furtherer

I was wrong, or I lied. This is the final cleanup.

bin/varnishtest/tests/r02976.vtc

 varnishtest "Detect probe interval inversion"
 
-barrier bprobe cond 2
-
-server s1 {
-	# 5 probe requests
-	rxreq
-	txresp
-	close
-	accept
-	rxreq
-	txresp
-	close
-	accept
-	rxreq
-	txresp
-	close
-	accept
-	rxreq
-	txresp
-	close
-	accept
+server s1 -repeat 5 { # probe requests
 	rxreq
 	txresp
-	close
-	accept
-	barrier bprobe sync
 } -start
 
 varnish v1 -cliok {param.set vcc_err_unref off}
@@ -41,4 +19,4 @@ varnish v1 -vcl {
 	}
 } -start
 
-barrier bprobe sync
+server s1 -wait