mlxsw: spectrum_switchdev: Set PVID correctly during VLAN deletion

When a VLAN is deleted from a bridge port we should not change the PVID
unless the deleted VLAN is the PVID.

Fixes: fe9ccc78

 ("mlxsw: spectrum_switchdev: Don't batch VLAN operations")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>