VSOCK: defer sock removal to transports

The virtio transport will implement graceful shutdown and the related
SO_LINGER socket option.  This requires orphaning the sock but keeping
it in the table of connections after .release().

This patch adds the vsock_remove_sock() function and leaves it up to the
transport when to remove the sock.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 4120b7a..4be4fbb 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1644,6 +1644,8 @@
 
 static void vmci_transport_release(struct vsock_sock *vsk)
 {
+	vsock_remove_sock(vsk);
+
 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->dg_handle)) {
 		vmci_datagram_destroy_handle(vmci_trans(vsk)->dg_handle);
 		vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;