net: dsa: tag_ocelot: use the dsa_xmit_port_mask() helper

The "ocelot" and "seville" tagging protocols populate a bit mask for the
TX ports, so we can use dsa_xmit_port_mask() to centralize the decision
of how to set that field.

This protocol used BIT_ULL() rather than simple BIT() to silence Smatch,
as explained in commit 1f778d500df3 ("net: mscc: ocelot: avoid type
promotion when calling ocelot_ifh_set_dest"). I would expect that this
tool no longer complains now, when the BIT(dp->index) is hidden inside
the dsa_xmit_port_mask() function, the return value of which is promoted
to u64.

Signed-off-by: Vladimir Oltean <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/dsa/tag_ocelot.c

···
 static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
 				   struct net_device *netdev)
 {
-	struct dsa_port *dp = dsa_user_to_port(netdev);
 	void *injection;
 
 	ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), &injection);
-	ocelot_ifh_set_dest(injection, BIT_ULL(dp->index));
+	ocelot_ifh_set_dest(injection, dsa_xmit_port_mask(skb, netdev));
 
 	return skb;
 }
···
 static struct sk_buff *seville_xmit(struct sk_buff *skb,
 				    struct net_device *netdev)
 {
-	struct dsa_port *dp = dsa_user_to_port(netdev);
 	void *injection;
 
 	ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), &injection);
-	seville_ifh_set_dest(injection, BIT_ULL(dp->index));
+	seville_ifh_set_dest(injection, dsa_xmit_port_mask(skb, netdev));
 
 	return skb;
 }