net/bnxt: fix MAC address setting when port is stopped

net/bnxt: fix MAC address setting when port is stopped

Driver destroys the VNIC when the port is brought down.
Port HW filter setting such as default MAC address and
unicast MAC filters will be applied when port is started.

Fixed to return success silently for these callbacks
when port is stopped.

Fixes: 39b88344e364 ("net/bnxt: fix enable/disable VLAN filtering")
Cc: stable@dpdk.org
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>