net: dsa: b53: fix VLAN ID for untagged vlan on bridge leave

The untagged default VLAN is added to the default vlan, which may be
one, but we modify the VLAN 0 entry on bridge leave.

Fix this to use the correct VLAN entry for the default pvid.

Fixes: fea83353 ("net: dsa: b53: Fix default VLAN ID")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250429201710.330937-6-jonas.gorski@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>