RDMA/ipoib: Remove NULL check before dev_{put, hold}

Coccinelle reports a warning

WARNING: NULL check before dev_{put, hold} functions is not needed

The reason is the call netdev_{put, hold} of dev_{put,hold} will check NULL
There is no need to check before using dev_{put, hold}

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Link: https://lore.kernel.org/r/ZjGDFatHRMI6Eg7M@octinomon.home
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: irenge

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -329,8 +329,7 @@ static struct net_device *ipoib_get_master_net_dev(struct net_device *dev)
 
 	rcu_read_lock();
 	master = netdev_master_upper_dev_get_rcu(dev);
-	if (master)
-		dev_hold(master);
+	dev_hold(master);
 	rcu_read_unlock();
 
 	if (master)