Suspicious pattern for use of function xt_register_template()

[Lukas Bulwahn]

Dear Florian, dear netfilter maintainers,

Commit fdacd57c79b ("netfilter: x_tables: never register tables by
default") on linux-next
introduces the function xt_register_template() and in all cases but
one, the calls to that function are followed by:

    if (ret < 0)
        return ret;

All these checks were also added with the commit above.

In the one case, for iptable_mangle_init() in
./net/ipv4/netfilter/iptable_mangle.c, this pattern was not followed.
This makes this ret assignment in this function a Dead Store and
hence, clang-analyzer warns about that.

Are we missing here an early return for a negative return value as
well, or is this case for iptable_mangle_init() in
./net/ipv4/netfilter/iptable_mangle.c special?


Best regards,

Lukas