tipc: add missing dev_put() on error in tipc_enable_l2_media

when tipc_own_id failed to obtain node identity,dev_put should
be call before return -EINVAL.

Fixes: 682cd3cf ("tipc: confgiure and apply UDP bearer MTU on running links")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/bearer.c

@@ -395,6 +395,7 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
 		tipc_net_init(net, node_id, 0);
 	}
 	if (!tipc_own_id(net)) {
+		dev_put(dev);
 		pr_warn("Failed to obtain node identity\n");
 		return -EINVAL;
 	}