Also remove the stale declaration of host_net_devices; the actual
definition was removed long ago in commit 7cc28cb06104 ("net: Remove
the deprecated 'host_net_add' and 'host_net_remove' HMP commands")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Thomas Huth <thuth@redhat.com>