netevent: remove automatic variable in register_netevent_notifier()

Remove automatic variable 'err' in register_netevent_notifier() and
return the result of atomic_notifier_chain_register() directly.

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/netevent.c

@@ -31,10 +31,7 @@ static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain);
  */
 int register_netevent_notifier(struct notifier_block *nb)
 {
-	int err;
-
-	err = atomic_notifier_chain_register(&netevent_notif_chain, nb);
-	return err;
+	return atomic_notifier_chain_register(&netevent_notif_chain, nb);
 }
 EXPORT_SYMBOL_GPL(register_netevent_notifier);