[SMACK] Build-time warning from Linux 5.6.2: unused variable ‘sip’

[Jordan Glover]

Hello, during build of Linux 5.6.2 (also happened on 5.5.x series)
gcc (9.3) prints following warning:

security/smack/smack_lsm.c: In function ‘smack_socket_connect’:
security/smack/smack_lsm.c:2838:24: warning: unused variable ‘sip’ [-Wunused-variable]
 2838 |   struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;

My kernel has set CONFIG_IPV6=n during build.

Jordan