vtc: Proper -start and -stop in c123

And finally, the test logs contain the complete VSL output for all four
transactions. It was an attempt at following the VSL in this test case
that led me to finding where the VSM status was lacking or incorrect.

bin/varnishtest/tests/c00123.vtc

@@ -31,10 +31,11 @@ client c1 {
 
 # in practice a little over fetch_chunksize is allocated
 varnish v1 -expect SM?.s0.c_bytes < 20000
+varnish v1 -vsl_catchup
 
 # reset s0 counters
-varnish v1 -cliok stop
-varnish v1 -cliok start
+varnish v1 -stop
+varnish v1 -start
 varnish v1 -expect SM?.s0.c_bytes == 0
 
 # content-length req.body streaming also needs one chunk
@@ -45,10 +46,11 @@ client c2 {
 } -run
 
 varnish v1 -expect SM?.s0.c_bytes < 20000
+varnish v1 -vsl_catchup
 
 # reset s0 counters
-varnish v1 -cliok stop
-varnish v1 -cliok start
+varnish v1 -stop
+varnish v1 -start
 
 # chunked req.body caching allocates storage for the entire body
 client c3 {
@@ -60,10 +62,11 @@ client c3 {
 } -run
 
 varnish v1 -expect SM?.s0.c_bytes > 100000
+varnish v1 -vsl_catchup
 
 # reset s0 counters
-varnish v1 -cliok stop
-varnish v1 -cliok start
+varnish v1 -stop
+varnish v1 -start
 
 # content-length req.body caching allocates storage for the entire body
 client c4 {
@@ -73,3 +76,4 @@ client c4 {
 } -run
 
 varnish v1 -expect SM?.s0.c_bytes > 100000
+varnish v1 -vsl_catchup