net: ena: fix error handling in ena_down() sequence

ENA admin command queue errors are not handled as part of ena_down().
As a result, in case of error admin queue transitions to non-running
state and aborts all subsequent commands including those coming from
ena_up(). Reset scheduled by the driver from the timer service
context would not proceed due to sharing rtnl with ena_up()/ena_down()

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>