mlxsw: spectrum_span: Ignore VLAN entries not used by the bridge in mirroring

Only VLAN entries installed on the bridge device itself should be
considered when checking whether a packet with a specific VLAN can be
mirrored via a bridge device. VLAN entries only used to keep context
(i.e., entries with 'BRIDGE_VLAN_INFO_BRENTRY' unset) should be ignored.

Fix this by preventing mirroring when the VLAN entry does not have the
'BRIDGE_VLAN_INFO_BRENTRY' flag set.

Fixes: ddaff504 ("mlxsw: spectrum: remove guards against !BRIDGE_VLAN_INFO_BRENTRY")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c

@@ -269,7 +269,8 @@ mlxsw_sp_span_entry_bridge_8021q(const struct net_device *br_dev,
 
 	if (!vid && WARN_ON(br_vlan_get_pvid(br_dev, &vid)))
 		return NULL;
-	if (!vid || br_vlan_get_info(br_dev, vid, &vinfo))
+	if (!vid || br_vlan_get_info(br_dev, vid, &vinfo) ||
+	    !(vinfo.flags & BRIDGE_VLAN_INFO_BRENTRY))
 		return NULL;
 
 	edev = br_fdb_find_port(br_dev, dmac, vid);