net: bridge: vlan: fix memory leak in __allowed_ingress

net: bridge: vlan: fix memory leak in __allowed_ingress

When using per-vlan state, if vlan snooping and stats are disabled,
untagged or priority-tagged ingress frame will go to check pvid state.
If the port state is forwarding and the pvid state is not
learning/forwarding, untagged or priority-tagged frame will be dropped
but skb memory is not freed.
Should free skb when __allowed_ingress returns false.

Fixes: a580c76d534c ("net: bridge: vlan: add per-vlan state")
Signed-off-by: Tim Yi <tim.yi@pica8.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20220127074953.12632-1-tim.yi@pica8.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>