net: dsa: reindent arguments of dsa_user_vlan_for_each()

These got misaligned after commit 6ca80638 ("net: dsa: Use conduit
and user terms").

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>