If we can't get the warmboot-finalizer state, don't exit (#15985)

In some cases, connecting to the device may fail for whatever reason. If
this happens, the current code returns an empty string as the
warmboot-finalizer state. There's a for-loop that exits when the
warmboot-finalizer state is no longer active. An empty string being
returned here breaks that.

To avoid that, don't exit this loop if we get an empty string.

Signed-off-by: Saikrishna Arcot <[email protected]>

ansible/roles/test/files/ptftests/py3/advanced-reboot.py

@@ -1061,7 +1061,7 @@ def check_warmboot_finalizer(self, finalizer_timeout):
         self.finalizer_state = self.get_warmboot_finalizer_state()
         self.log('warmboot finalizer service state {}'.format(self.finalizer_state))
         count = 0
-        while self.finalizer_state == 'activating':
+        while self.finalizer_state == 'activating' or self.finalizer_state == '':
             self.finalizer_state = self.get_warmboot_finalizer_state()
             self.log('warmboot finalizer service state {}'.format(self.finalizer_state))
             time.sleep(10)