net: aquantia: fix removal of vlan 0

Due to absence of checking against the rx flow rule when vlan 0 is being
removed, the other rule could be removed instead of the rule with vlan 0

Fixes: 7975d2af

 ("net: aquantia: add support of rx-vlan-filter offload")
Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>