xen: do not disable netfront in dom0

Netfront driver can be also useful in dom0, eg when all NICs are assigned to
some domU (aka driver domain). Then using netback in domU and netfront in dom0
is the only way to get network access in dom0.
Signed-off-by: NMarek Marczykowski <marmarek@invisiblethingslab.com>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/xen-netfront.c

@@ -1962,9 +1962,6 @@ static int __init netif_init(void)
 	if (!xen_domain())
 		return -ENODEV;
 
-	if (xen_initial_domain())
-		return 0;
-
 	if (xen_hvm_domain() && !xen_platform_pci_unplug)
 		return -ENODEV;
 
@@ -1977,9 +1974,6 @@ module_init(netif_init);
 
 static void __exit netif_exit(void)
 {
-	if (xen_initial_domain())
-		return;
-
 	xenbus_unregister_driver(&netfront_driver);
 }
 module_exit(netif_exit);