Revert "net: use struct_group to copy ip/ipv6 header addresses"

This reverts commit cb7893c8 which is
commit 58e0be1e upstream.

It causes a CRC change, in order to just remove a build warning that is
not correct.  So just revert it as it's not needed in the Android kernel
at all.

Bug: 161946584
Fixes: cb7893c8 ("net: use struct_group to copy ip/ipv6 header addresses")
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I68a5f94066911a49dd8cb04d38291e27cb446f6f