netfilter: nfnetlink_osf: fix module autoload

[ Upstream commit 62f9a68a36d4441a6c412b81faed102594bc6670 ]

Move the alias from xt_osf to nfnetlink_osf.

Fixes: f9324952 ("netfilter: nfnetlink_osf: extract nfnetlink_subsystem code from xt_osf.c")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>