Revert "RDMA/core: Fix ENODEV error for iWARP test over vlan"

The citied commit in Fixes line caused to regression for udaddy [1]
application. It doesn't work over VLANs anymore.

Client:
  ifconfig eth2 1.1.1.1
  ip link add link eth2 name p0.3597 type vlan protocol 802.1Q id 3597
  ip link set dev p0.3597 up
  ip addr add 2.2.2.2/16 dev p0.3597
  udaddy -S 847 -C 220 -c 2 -t 0 -s 2.2.2.3 -b 2.2.2.2

Server:
  ifconfig eth2 1.1.1.3
  ip link add link eth2 name p0.3597 type vlan protocol 802.1Q id 3597
  ip link set dev p0.3597 up
  ip addr add 2.2.2.3/16 dev p0.3597
  udaddy -S 847 -C 220 -c 2 -t 0 -b 2.2.2.3

[1] https://github.com/linux-rdma/rdma-core/blob/master/librdmacm/examples/udaddy.c

Fixes: 5069d7e ("RDMA/core: Fix ENODEV error for iWARP test over vlan")
Reported-by: Leon Romanovsky <[email protected]>
Closes: https://lore.kernel.org/all/20241110130746.GA48891@unreal
Link: https://patch.msgid.link/bb9d403419b2b9566da5b8bf0761fa8377927e49.1731401658.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <[email protected]>

Author: rleon

drivers/infiniband/core/addr.c

@@ -269,8 +269,6 @@ rdma_find_ndev_for_src_ip_rcu(struct net *net, const struct sockaddr *src_in)
 		break;
 #endif
 	}
-	if (!ret && dev && is_vlan_dev(dev))
-		dev = vlan_dev_real_dev(dev);
 	return ret ? ERR_PTR(ret) : dev;
 }