Used shared init with LinuxKit

With https://github.com/linuxkit/linuxkit/pull/2500 the init script
can be used for both bare metal and in Docker.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

examples/linuxkit.yml

@@ -1,16 +1,15 @@
 kernel:
   image: "linuxkit/kernel:4.9.41"
   cmdline: "console=ttyS0"
-init:
-  - linuxkit/init:c7d651da1a5e308c757bc61ce6a41804ea843426
-  - linuxkit/runc:dfc0437161843bc0dfeb334cda7ffd6a18b76bcd
-  - linuxkit/containerd:d136569c66ce041853d762b7032456419e580efe
-  - linuxkit/ca-certificates:e44b0a66df5a102c0e220f0066b0d904710dcb10
 onboot:
   - name: dhcpcd
     image: "linuxkit/dhcpcd:f3f5413abb78fae9020e35bd4788fa93df4530b7"
     command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
 services:
+  - name: getty
+    image: linuxkit/getty:797cb79e0a229fcd16ebf44a0da74bcec03968ec
+    env:
+     - INSECURE=true
   - name: rngd
     image: "linuxkit/rngd:558e86a36242bb74353bc9287b715ddb8567357e"
 trust: