pcs stonith sbd watchdog test fails with "Failed to initialize watchdog!!!" when Pacemaker is running with sbd enabled

Issue

• The pcs stonith sbd watchdog test command succeeds when the cluster is stopped. When the cluster is running with sbd enabled, the command fails as follows:

# pcs stonith sbd watchdog test
Warning: This operation is expected to force-reboot this system without following any shutdown procedures.
Proceed? [no/yes]: yes
System will reset shortly
Error: Unable to initialize test of the watchdog: Initializing /dev/watchdog with a reset countdown of 5 seconds ...
Failed to initialize watchdog!!!