net: bridge: propagate extack through store_bridge_parm

The bridge sysfs interface stores parameters for the STP, VLAN,
multicast etc subsystems using a predefined function prototype.
Sometimes the underlying function being called supports a netlink
extended ack message, and we ignore it.

Let's expand the store_bridge_parm function prototype to include the
extack, and just print it to console, but at least propagate it where
applicable. Where not applicable, create a shim function in the
br_sysfs_br.c file that discards the extra function argument.

This patch allows us to propagate the extack argument to
br_vlan_set_default_pvid, br_vlan_set_proto and br_vlan_filter_toggle,
and from there, further up in br_changelink from br_netlink.c.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>