be2net: fix MAC address modification for VF

Currently, the VFs by default don't have the privilege to modify MAC address.
This will change in a subsequent fix wherein VFs will have the ability to
modify MAC/VLAN filters.

Fix be_mac_addr_set() logic to support MAC address modification on a
privileged VF too.

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