Smack: Remove unnecessary variable initialization

The initialization of rc in smack_from_netlbl() is pointless.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security/smack/smack_lsm.c

@@ -3870,7 +3870,7 @@ static struct smack_known *smack_from_netlbl(struct sock *sk, u16 family,
 	struct netlbl_lsm_secattr secattr;
 	struct socket_smack *ssp = NULL;
 	struct smack_known *skp = NULL;
-	int rc = 0;
+	int rc;
 
 	netlbl_secattr_init(&secattr);