net: socket: remove register_gifconf

[ Upstream commit b0e99d03 ]

Since dynamic registration of the gifconf() helper is only used for
IPv4, and this can not be in a loadable module, this can be simplified
noticeably by turning it into a direct function call as a preparation
for cleaning up the compat handling.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 5641c751 ("net: enetc: deny offload of tc-based TSN features on VF interfaces")
Signed-off-by: Sasha Levin <sashal@kernel.org>