ipv4: Remove redundant !ifa->ifa_dev check.

Now, ifa_dev is only set in inet_alloc_ifa() and never
NULL after ifa gets visible.

Let's remove the unneeded NULL check for ifa->ifa_dev.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240809235406.50187-4-kuniyu@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c

@@ -3185,8 +3185,7 @@ netxen_list_config_ip(struct netxen_adapter *adapter,
 	struct list_head *head;
 	bool ret = false;
 
-	dev = ifa->ifa_dev ? ifa->ifa_dev->dev : NULL;
-
+	dev = ifa->ifa_dev->dev;
 	if (dev == NULL)
 		goto out;
 
@@ -3379,7 +3378,7 @@ netxen_inetaddr_event(struct notifier_block *this,
 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
 	unsigned long ip_event;
 
-	dev = ifa->ifa_dev ? ifa->ifa_dev->dev : NULL;
+	dev = ifa->ifa_dev->dev;
 	ip_event = (event == NETDEV_UP) ? NX_IP_UP : NX_IP_DOWN;
 recheck:
 	if (dev == NULL)

drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c

@@ -4146,7 +4146,7 @@ qlcnic_inetaddr_event(struct notifier_block *this,
 
 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
 
-	dev = ifa->ifa_dev ? ifa->ifa_dev->dev : NULL;
+	dev = ifa->ifa_dev->dev;
 
 recheck:
 	if (dev == NULL)

net/ipv4/devinet.c

@@ -234,8 +234,7 @@ static void inet_rcu_free_ifa(struct rcu_head *head)
 {
 	struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head);
 
-	if (ifa->ifa_dev)
-		in_dev_put(ifa->ifa_dev);
+	in_dev_put(ifa->ifa_dev);
 	kfree(ifa);
 }