bridge: always declare tunnel functions

When CONFIG_BRIDGE_VLAN_FILTERING is disabled, two functions are still
defined but have no prototype or caller. This causes a W=1 warning for
the missing prototypes:

net/bridge/br_netlink_tunnel.c:29:6: error: no previous prototype for 'vlan_tunid_inrange' [-Werror=missing-prototypes]
net/bridge/br_netlink_tunnel.c:199:5: error: no previous prototype for 'br_vlan_tunnel_info' [-Werror=missing-prototypes]

The functions are already contitional on CONFIG_BRIDGE_VLAN_FILTERING,
and I coulnd't easily figure out the right set of #ifdefs, so just
move the declarations out of the #ifdef to avoid the warning,
at a small cost in code size over a more elaborate fix.

Fixes: 188c67dd ("net: bridge: vlan options: add support for tunnel id dumping")
Fixes: 569da082

 ("net: bridge: vlan options: add support for tunnel mapping set/del")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20230516194625.549249-3-arnd@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>