be2net: fix failure case in setting flow control

When the FW cmd to set flow control fails, the adapter state must simply
reflect the old values.

Signed-off-by: Kalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>