net: bridge: Exit if multicast_init_stats fails

If br_multicast_init_stats() fails, there is no need to set lockdep
classes. Just return from the error path.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20240227182338.2739884-2-leitao@debian.org


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