net: dsa: b53: fix flushing old pvid VLAN on pvid change

[ Upstream commit 083c6b28 ]

Presumably the intention here was to flush the VLAN of the old pvid, not
the added VLAN again, which we already flushed before.

Fixes: a2482d2c ("net: dsa: b53: Plug in VLAN support")
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/20250429201710.330937-5-jonas.gorski@gmail.com


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