security: smack: Fix indentation in smack_netfilter.c

Aligned parameters in the function declaration of smack_ip_output
to adhere to the Linux kernel coding style guidelines.

The parameters of the smack_ip_output function were previously misaligned,
with the second and third parameters not aligned under the first parameter.
This change corrects the indentation, improving code readability and
maintaining consistency with the rest of the codebase.

Signed-off-by: GiSeong Ji <jiggyjiggy0323@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>