iavf: in iavf_down, don't queue watchdog_task if comms failed

iavf: in iavf_down, don't queue watchdog_task if comms failed

The reason for queueing watchdog_task is to have it process the
aq_required flags that are being set here. If comms failed, there's
nothing to do, so return early.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231027175941.1340255-4-jacob.e.keller@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>