bnxt_en: Call bnxt_approve_mac() after the PF gives up control of the VF MAC.

When the PF is no longer enforcing an assigned MAC address on a VF, the
VF needs to call bnxt_approve_mac() to tell the PF what MAC address it is
now using.  Otherwise it gets out of sync and the PF won't know what
MAC address the VF wants to use.  Ultimately the VF will fail when it
tries to setup the L2 MAC filter for the vnic.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>