rtnetlink: remove an unneeded test

We know that "dev" is a valid pointer at this point, so we can remove
the test and clean up a little.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/rtnetlink.c

@@ -1867,10 +1867,10 @@ replay:
 		else
 			err = register_netdevice(dev);
 
-		if (err < 0 && !IS_ERR(dev))
+		if (err < 0) {
 			free_netdev(dev);
-		if (err < 0)
 			goto out;
+		}
 
 		err = rtnl_configure_link(dev, ifm);
 		if (err < 0)