It is possible (but unlikely) that FW was busy and missed a heartbeat
check but is still alive and will process the pending request, so don't
clean the dev_cmd in this case.  This occasionally occurs when working
with a card that is supporting many devices and is trying to shut them
all down at once, but still wants to see that last LIF disable request.

Fixes: 97ca4865 ("ionic: add heartbeat check")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>