be2net: Changing MAC Address of a VF was broken.

Allow for MAC Address change of VF(SR-IOV case) on the fly- First add and then
delete MAC Address to allow for 'out of pool' errors.
When MAC Addr configured from a VM, the MAC on the NIC will aleady have
the supplied MAC,so just copy the supplied MAC to the netdev structure
before returning success to the stack

Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>