be2net: fix certain cmd failure logging

Some (older)versions of cards/fw may not recognize certain cmds and
return illegal/unsupported errors. As long as the driver can handle
this gracefully there is no need to log an error msg.
Also finetuned 2 existing error log messages.

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