[NETFILTER]: nf_log: make nf_log_unregister_pf return void

Since the only user of nf_log_unregister_pf (nfnetlink_log) doesn't
check the return value, change it to void and bail out silently when
a non-existant address family is supplied.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter.h

@@ -172,7 +172,7 @@ struct nf_logger {
 
 /* Function to register/unregister log function. */
 int nf_log_register(int pf, struct nf_logger *logger);
-int nf_log_unregister_pf(int pf);
+void nf_log_unregister_pf(int pf);
 void nf_log_unregister_logger(struct nf_logger *logger);
 
 /* Calls the registered backend logging function */

net/netfilter/nf_log.c

@@ -40,19 +40,16 @@ int nf_log_register(int pf, struct nf_logger *logger)
 }		
 EXPORT_SYMBOL(nf_log_register);
 
-int nf_log_unregister_pf(int pf)
+void nf_log_unregister_pf(int pf)
 {
 	if (pf >= NPROTO)
-		return -EINVAL;
-
+		return;
 	spin_lock(&nf_log_lock);
 	rcu_assign_pointer(nf_logging[pf], NULL);
 	spin_unlock(&nf_log_lock);
 
 	/* Give time to concurrent readers. */
 	synchronize_rcu();
-
-	return 0;
 }
 EXPORT_SYMBOL(nf_log_unregister_pf);