nfp: disable FW on reconfiguration errors

Since we no longer need to keep the FW enabled for .ndo_close()
to work we can always stop FW after reconfiguration failure.
This seems to make most FWs more resilient to faults (at least
in error injection scenarios).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>