test: make dfuzzer less verbose

Otherwise it oversaturates the journal, which in some cases can't keep
up with the load of messages (due to the performance penalty caused by
sanitizers), and gets killed by a watchdog.

test/units/testsuite-21.sh

@@ -72,7 +72,7 @@ mount -t tmpfs -o size=50M tmpfs /var/lib/machines
 for bus in "${BUS_LIST[@]}"; do
     echo "Bus: $bus (system)"
     systemd-run --pipe --wait \
-                -- dfuzzer -v -b "$PAYLOAD_MAX" -n "$bus"
+                -- dfuzzer -b "$PAYLOAD_MAX" -n "$bus"
 
     # Let's reload the systemd daemon to test (de)serialization as well
     systemctl daemon-reload
@@ -83,7 +83,7 @@ umount /var/lib/machines
 for bus in "${SESSION_BUS_LIST[@]}"; do
     echo "Bus: $bus (session)"
     systemd-run --machine 'testuser@.host' --user --pipe --wait \
-                -- dfuzzer -v -b "$PAYLOAD_MAX" -n "$bus"
+                -- dfuzzer -b "$PAYLOAD_MAX" -n "$bus"
 
     # Let's reload the systemd user daemon to test (de)serialization as well
     systemctl --machine 'testuser@.host' --user daemon-reload