regression test ignores log output from the reader thread about free lists,

as with the writer thread, since these are not relevant to the regression
and are not predictable

src/test/regress.sh

@@ -18,12 +18,12 @@ if [ "$CKSUM" != "4102580059 20793538 $OUT" ]; then
 fi
 
 # sed removes the version/revision from the "initializing" line.
-# grep removes logs from the writer thread about returns to free lists,
-# which are not relevant to the regression, and may appear at different
-# places in the log (due to multi-threading).
-CKSUM=$( sed -e 's/\(initializing\) \(.*\)/\1/' $LOG | grep -v 'Writer: returned' | cksum )
+# grep removes logs by the threads about free lists, which are not
+# relevant to the regression, and are not predictable from one run to
+# the next.
+CKSUM=$( sed -e 's/\(initializing\) \(.*\)/\1/' $LOG | egrep -v 'Writer: returned|Reader: took' | cksum )
 
-if [ "$CKSUM" != '214907488 66951871' ]; then
+if [ "$CKSUM" != '469328279 66951401' ]; then
     echo "ERROR: Regression test varnishevent log incorrect cksum: $CKSUM"
     exit 1
 fi