net/ipv4: fix macro definition sk_for_each_bound_bhash

The macro sk_for_each_bound_bhash accepts a parameter
__sk, but it was not used, rather the sk2 is directly
used, so we replace the sk2 with __sk in macro.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://patch.msgid.link/20240823070453.3327832-1-lihongbo22@huawei.com


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