net: Rename non_vlan_clients to net_clients

net: Rename non_vlan_clients to net_clients

There is no longer a distinction between vlan clients and non-vlan
clients in the net core.  The net core only knows about point-to-point
clients which are connected to a peer.  It's time to rename the global
list of net clients since it no longer refers to vlans at all.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>