qed: Handle management FW error

Handle MFW (management FW) error response in order to avoid a crash
during recovery flows.

Changes from v1:
- Add "Fixes tag".

Fixes: tag 5e7ba042

 ("qed: Fix reading stale configuration information")
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Shai Malin <smalin@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>